Cubase is what I've settled on after playing around and testing. While it is pricey to be sure (currently Sweetwater has a crossgrade for $255 which is by far the lowest prince I've ever seen it for) and I hate the requirement of a hardware dongle, it is good software that is seriously worth looking at.
 
It's fast, stable, usable and all that basic stuff that you would expect from any DAW (but not necessarily get). So I'll talk briefly about what I feel makes it really good above and beyond the basics:
 
--The UI. It looks kinda spartan at first and some might say ugly, but really it is very usable and flexible. I would compare it to something like Microsoft Excel: Designed to get a job done and not get in your way. I find it very easy to get the information you need, and very easy to customize to my preferred workflow. Also the GUI is hardware accelerated (using your GPU) so it is very smooth in operation.
 
--MIDI capabilities. Sonar was always one of the best platforms for handling MIDI, IMO, but Cubase is at least as good, maybe even better. Anything else I tried felt like a step backwards. Also it handles importing MIDI controls to automation data better than Sonar.
 
--VST support. No surprise here, since they made the standard, but it really handles VSTs well. From simple things like an auto-blacklist for VSTs known to cause stability issues (you can override, of course) to things like automatically dealing with channel handling for VST3s that support it, it is nice.
 
--Speaking of channel handling, real, true, surround support. While Sonar has surround channels/buses, it has always been a limited form of surround support since it can't handle multi-channel VSTs. Cubase handles them fine. Things like Waves' IR360 work in Cubase, one of the few DAWs it will work with (ProTools, Audition, Pyramix and Reaper being the others). For a number of VST3s (like the Melda Productions ones) they will just work with the surround channels by choosing surround mode in them. Only thing I can ding it on here is that it only supports 6 channels max (either 5.1 or 6.0). To get more than that you have to get Nuendo, whereas Sonar would do 7.1. Also it's surround panner could stand to be better (again Nuendo has a good one) but it gets the job done and seems to be more proficient than Sonar's overall.
 
--The included effects are tremendous. They are easy to use, sound good, and automatically scale from mono to surround with no effort on your part (just put them on the track and they select the proper configuration). In particular REVlation and REVerence their algo and convolution reverbs are tremendous. If I had these, I probably never would have bought IR-1 or H-Reverb.
 
--You can use old versions with new licenses. I haven't tested this yet personally, but that is the info on their forums, and all the old versions can be downloaded from their site. So if you need to step back to an earlier version, for whatever reason, you should be able to do so. Even unsupported versions still seem to be available. You can download the full version of Cubase 4, which is from 2006, on the site.
 
--Good hardware integration. It seems to integrate well with MCU/HUI devices as is, they have their own controller that is pricey for what it is but looks good, and Yamaha makes some ultra-high end control systems if you wanna go nuts (those need Nuendo, I think though if you can afford them the cost of Nuendo is not a big deal).
 
Only real thing I can complain about overall so far is that it is very ASIO-centric, as you'd expect given again, they invented it. If you have a soundcard with good ASIO drivers, no issue. However if you don't, it doesn't offer the nice WASAPI/WDM/MME support Sonar does. Also the included "Generic Lowlatency ASIO driver) is garbage. However, ASIO4ALL works very well with it if you are trying to use a non-ASIO card. I'm using it with the HDMI output on my video card and it works great in event mode for low latency surround.
 
 
All in all, though I'm really sad about Sonar going away, I'm pleased with Cubase. It feels like it does most of the important stuff at least as well as Sonar.
 
Ongoing price doesn't look too bad either. Looks like they release a new "paid update" about once a year, and they cost $60-$100 (depending on if they are a full 1.0 or a half 0.5) to purchase. If you skip one, just add in the cost of the last one, and you can go further back than that. So 9.5, the current version, costs $60 from 9.0, $160 from 8.5, $200 from 7-8, and $300 from 4-6.5. Not too much per year to keep current, and not too much to true up if you let it lapse a few years and then decide you want to get back to the latest.
 
They also count basically all of what you've spent towards upgrades to bigger versions. So if you own Artist, which is $330, you pay $250 to upgrade to Pro, which is $580 retail. Likewise if you own Pro you pay $1300 to get Nuendo, which is $1900 retail. So you can buy their bigger stuff at any time without feeling like you wasted a bunch of money.
 
At any rate, give it a look if you can. I already had an eLicenser since I got Halion Sonic years ago. While I really don't like dongles, I've resigned myself to them and the drivers are stable and unproblematic. It is a program worth checking out, and the one I decided I like best.