mudgel
There are a few features you only get in Pro Tools HD that have been in Sonar for years and that's a big slice of bucks every year, $399 if you absolutely need to have those few features. Way more than Sonar Platinum. I know I have it and pay for the privilege every year to have HD. If I don't update and want to buy back in that's $899.
Yes, PT HD is another story. Avid was very back and forth about that too. On track monitoring and VCA's were removed for a while when spreadsheet guys were in the clouds somewhere thinking they could charge anything for nothing, like chuckebaby was into a bit.
Ordinary PT12 with 128 tracks is probably ok for most people. And most outrageous removals back in place.
I followed Avid forum for a year around then, and there were some other stuff in HD too that is beyond my understanding how they even succeed in charging so much for those cards.
I saw some episodes on Pensados Place where some usage of PT in the field, live tv shows and whatnot. You don't take a chance under those those conditions. If you having something that works you are not likely changing it.
Sonar is much more resource efficient than PT for sure. I ran PT as trial on a rather weak laptop and could run Sonar, Reaper and Cubase just fine - and PT just about started up. I think Avid are Mac guys and PT run much better on Mac, and Windows version is just for courtesy being large market. Just like Digital Performer in cpu on Windows as an estimate - also some work before MOTU get that optmized, I think. DP was double cpu for even less amount of plugins in a project. Maybe PT was a bit better than that.