best laptop for the buck

 Usually the Mac architecture runs on a lower CPU.  If you want to stay with Windows look for a gaming type laptop.
My own reality tells me laptops aren't great for extensive music production unless you get into the $2000+ range. I wouldn't waste that on a laptop when I could build a killer desktop and run an RME unit.
 Higher specs also mean more battery consumption. One of the reason I would recommend a Mac Book Pro is the battery is of a better quality. You can run Bootcamp.
 

Typical off-the-shelf laptops don't make good DAWs.
A laptop that's anywhere close to the speed of a well-configured tower starts at ~$2k (as KiteCrazy1 mentioned).
Unless you absolutely must have a laptop, I'd encourage you to get a tower.  You'll get FAR more bang-for-the-buck.
 
Off-the-shelf machines typically have motherboards with "dumbed down" BIOS.
Certain parameters that allow super low/consistent DPC Latency are not exposed.
This is done to prevent less tech-savvy users from fouling up their machine.
In this scenario, there's no way to achieve the low/consistent DPC Latency of a quality motherboard.
If you're wanting to run heavy loads at the smallest ASIO buffer sizes, it's critical to have low/consistent DPC Latency.
 
Off-the-shelf machines are built for general-purpose users (Office, Facebook, YouTube, Email, etc).
This user will never notice a 2ms hiccup in data-flow.
For the person running a heavy load at a 64-sample ASIO buffer size, that's a drop-out.
 
For high-performance scenarios, you're best off with a custom machine where each component is chosen for maximum performance and minimal noise.
 

Hi Simon,
 
You're not stepping on any toes...   
I don't disagree with any of the points you make.
 
Certainly the OP needs to start with a rock-solid audio interface.
 
Due to the tight physical space, performance compromises are made with laptops (to keep CPU temps in check).
That boils down to a lot of CPU throttling.  This causes high DPC Latency, etc.
This goes against everything we're looking for in a DAW (maximum sustained thru-put... with no hiccups in data-flow)
If you're not running at smaller ASIO buffer sizes... and you're not pushing the machine hard, this is less of a factor.
 
The best custom laptops allow you to use a desktop CPU... and allow custom BIOS (which provides all parameters necessary to achieve low/consistent DPC Latency).
This is the closest you'll get to the performance of a well-configured tower/rack.
Downside is it's not small... the monitor isn't touch-screen... and the cost is significant.
 
If performance is any type of priority, unless you absolutely must have a laptop (flying, etc), I'd recommend a tower/rack based DAW.  All the performance you want/need (with none of the limitations)... 
 
 

Looks like I'm keeping the i7 5500u, 8G, 1TB laptop.  I ran some projects with more tracks, plugins (pc and effects), and vst instruments (cw's latest) than I typically use.  Sonar cpu load meter was under 30% on the 4 threads (note the cpu is dual core??).  I think Sonar and Windows 10 (turn off the crap) run much lighter these days.  Tested with usb audio device (asio) latency ~9ms and wifi off and no Bluetooth.  Now I have to decide whether or not to update the desktop to Win10 from 8.1.  Also note when I ran the install for the off the shelf laptop I went with custom install vs typical install and was able to prevent the installation of a lot of crape.  I couldn't find a win 10 dlc latency checker.  If I do I'll let you know. 
 
Just a FYI.

I'm not easily impressed with Laptops (I hate the keyboard on a laptop).  My DAW system is a desktop.  But, last summer I bought a new laptop to use for "on site" recordings.  It is a Dell Inspiron 15, 5577 model that Dell sells as a "gaming" laptop.  It is a 7th gen i5 and comes with a 250GB M.2 SSD.  It has space to add a laptop hard drive or another SSD.  I'm impressed with this laptop as it "visually" boots as fast as my Desktop with SSD and loads programs the same way.  I have installed a second 500GB SSD and have two copies (dual boot) of Win 10, one for regular PC applications and the other with minimum on it to run Sonar Platinum.  When I run Sonar (and now also Studio One 3) its on the second copy with has nothing on it except Win 10 and the DAW software (Wi-Fi NIC is disabled).  Latency Mon shows the DAW Win10 as very clean.
 
One thing, I only "record" with this system.  The recordings are transferred to my desktop DAW for any processing.  I only have the basic Sonar Platinum installed, no additional add-ons.  

Some old threads resurrected today...   
 
The problem with laptops is the performance throttling that's done to keep heat in check (due to extremely tight space enclosures).  This is the reason why "mobile" processors exist.
ie: For DAW purposes, the 7700K is a much better performer than the 7700HQ.
 
Working at ultra low audio latency is "where the wheels fall off" with most laptops.
If working at ASIO buffer sizes smaller than 256 samples is the end goal (especially running heavy loads), you're not going to do that reliably with an inexpensive laptop. 
 
 
If the goal is to run heavy loads at a 64-sample ASIO buffer size or smaller, your choices are extremely limited.
These laptops are running desktop CPUs (not mobile)... and they're the closest you'll get to desktop level performance in a laptop.  The downside; they're $2000+, large/heavy, and battery charge doesn't last long.
 
A personal example:
I want to use Ableton Live on stage (to trigger audio bits, host soft-synths, allow playing to click-tracks, etc)... and to be able to immediately/seamlessly switch between songs.  
Live offers some amazing features for this purpose.
I want to be able to trigger audio/samples and virtual-instruments at ASIO buffer size of 64-samples (or lower) so the timing/feel is extremely tight.  This is the back-breaker.
Even a well equipped laptop (7700HQ, 16GB RAM, dedicated M.2 Ultra SSD for audio/samples) will struggle.
My solution was to build a small mini-ITX Cube... using a 21" multi-touch monitor.
The guys in the band looked at the Cube last gig... asked what it was... and thought I was crazy.  
It's more cartage than a laptop, but the performance is liberating.
At a 48-sample ASIO buffer size (RME Fireface UFX), I can load The Grandeur into Kontakt, step on the sustain pedal, and gliss up/down the keyboard like a mad-man... and there are *zero* glitches/hiccups.
If a machine can handle that type of performance stress... it's not going to ever glitch under normal (even extreme) performance conditions.
 
Side Note:
Even though The Grandeur may not be the ultimate piano sample library, it's just plain enjoyable to play with such tight/responsive timing.
 
If you aren't aware of what Ableton Live can do (in live performance), watch some YouTube videos where guys are immediately/seamlessly switching between advanced sample-libraries and instruments, using Scenes to automate ALL switching (super simple to execute complex changes), using Scenes to automatically switch tempo for each song (making it practical to setup/use click-tracks), etc.  The possibilities are amazing...
 

     HP Spectre 360 2 in 1 16 GB 512 SSD may not work out as well as I hoped. It features a 1.9 ghz - 4 ghz "turbo" which backs off when the fan speed increases. Okay as long as running around (edit) 12 latency at 44.1 ghz sample rate 256 ghz buffer size, been trying to get by with around (edit) 6 latency 44.1 ghz / 128 and get an occasional warning for cpu overload when the fan turns up.
    So far just running small project to learn Cubase, not sure how well it will handle additional tracks and plugs. I may have to employ CPU saving techniques to get by with this laptop, wouldn't recommend it for DAW at this point.
 
 
For what it's worth, Ron