Don't Forget The GUIs in your Post SONAR Determination.

It's hard to ignore the competitors' GUIs. I've been demoing lots and every one so far has made me go "Ugh...".

I had a look at other DAW's before I jumped fully into the SONAR adventure (before I upgraded from X3 to Platinium). And to me there was none that is so clearly arranged like Sonar. Either things are so small that I nearly can't see them on my laptop screen (I often work on the laptop) or you can just see 2 to 3 tracks at once. That is really no option to me!
Another issue in some other DAWs is that you do not have a good overview of the plugins set to a track.
And what is absolutly a candy for me in Sonar is the export feature. You have a lot of options, especially for simply exporting single tracks. That is missing in many other DAWs where you just can export the whole mix or selected tracks going thru the master, ugh.
All in all I do not think that I would ever find another fitting DAW at all. I just hope that Sonar will run on my PCs for life time (mine).

Yeah
DITTO

sorry, I haven't found any DAW with nearly as nice a GUI as Sonar's.  I think a redesign to look like all the others is a step in the WRONG direction.  If anything, make it more useable with touch-screens, make a  special view for those with touch screens with larger-print menus and larger versions of the tiny controls, but the current layout is phenomenal.  Skylight is a great feature, and the enhancements starting with Sonar X1 were very beneficial.

I prefer functional GUIs that respect screen real estate resource.
I couldn't care if it used standard Windows components if done right.
 
A pretty GUI is essential for sales, but after continually working with
a UI for hours, days and months, having to close windows to make 
space to open other ones, well, it just kills my motivation.
 

Also consider the UI after you've used it for a time. The following isn't about computer UIs, but I think it's germane.
 
Some decades ago, Denny's Restaurants hired a consulting firm to help it pick a new color scheme for its stores. The twin requirements were that, on initial entry, hit all of the right buttons (bright, warm, inviting, blah, blah, blah), but after a short time became unconsciously slightly disturbing (gotta turn tables!). After a bunch of testing, they came up with a black/orange combo. It did what it was designed to do. Customers liked the refresh! They just didn't notice that they weren't hanging around quite as long. But the outdoor sign stayed yellow and red. Why? Those two colors make use eat!
 
Moral of the story?
 
Something that looks good initially can become a subconscious irritant.
 
With Studio One, I am still a little put off by all of the bright track colors I see in videos, but I'm beginning to see the value of it in comping, for example. I prefer the brighter pastel colors (if that's not an oxymoron). But what I'm really getting comfortable with is the 50 Shades Of Grey (well, not that many) in the base UI (without all of the user track coloring added). I find it easy to read and not eye fatiguing.

During testing new DAWs I've come across a somewhat related issue - in a few of them the Nugen ISL2 limiter causes an Open GL error and crashes the DAW. No issue ever with Sonar, and a couple others. 
 
Maybe a graphics driver issue, I'm using the onboard Intel graphics (I use the available slots for a firewire card and 2 UAD2 cards) and apparently it's at the latest version, but maybe it's not a graphics driver issue - it prolly is :) - but I don't want to have to take the time right now to address that during intense DAW-s/hopping.