I do think I understand that Jim Roseberry runs X1 with no problem. (correct me if I am wrong... I was wrong once)
I've had good luck with X1 (from the beginning).
I think the reasons why are numerous:
-Latest generation hardware (dedicated DAW - well configured/tweaked)
-Rock-solid audio interface
-Work methods - I do a balance of audio and virtual instrument tracks (don't use Audio Snap, V-vocal, or StepSeq)
-My plugin collection is pared down to what I absolutely need (Waves SSL, T-Racks 3 singles, Lexicon PCM, Amplitube 3, Komplete 7, Omnisphere, Ivory-II, Korg M1)
Note that I'm running a clean install of Win7x64... and that I don't have multiple apps sharing C++ runtimes.
Bridged 32Bit plugins can cause a multitude of problems. If you're having major issues, try running the 32Bit version of X1.
If things run much better, then your particular 32Bit plugins may not cope well bith BitBridge.
If that's the case, you can try using jBridge... or find x64 replacements for those plugins.
To be clear, I won't say I've never experienced a X1 crash.
I experienced a crash when browsing/switching between our Jet-City drumkit components... and the Neil Pear collection... when running Kontakt 4.23. I've seen some flakey behavior reported by folks across numerous host apps... so I tend to think Kontakt 4.23 was the culprit.
Otherwise, I do experience Teleport related errors when closing X1. Note that these don't affect save... and have no affect on stability and don't cause lockups/etc. It's nothing more than an annoyance (benign).
When I mix (again) it's a balance of audio and virtual instrument tracks.
I use volume and send automation (not overly complex - both clip and track). I make use of per-clip fades/cross-fades.
Basically, linear style straight-up tracking/editing/mixing...
To be clear, I'm not saying X1 is perfect or is working great for everyone.
But X1 is working well for me...