I am a Sonar 8.5 Producer user and I'm considering between 2 options - upgrading to X2, or starting to use the Reaper DAW instead. 8.5 has several bugs and omissions that have led me to consider switching, but I'm out of touch with what X2 offers, hence this post.
 
So, my specific questions are:

1. Does X2 support the ability to split a clip (and all grouped clips) and automatically crossfade at the split? (Ideally with a configurable crossfade length.)
2. Does X2 support the ability to move audio within a clip (and all grouped clips), without moving the clip? (In 8.5 I would have to slip edit the start, then the end by the same amount, and then move the clip back to its original position) EDIT: Turns out that this is possible in 8.5 with Shift-Alt- Drag.
3. Is it possible in X2 to apply FX to track folders, or to have a fader on them, or do I still have to use a bus for that?
4. Can X2 take one incoming MIDI CC message (eg. CC7) and either record it or play it back as 2 CCs (eg. CC7 and CC11)? I'd use this with synths that have separate volume and expression controls, to be operated with one expression wheel in real time.
5. In your opinion, have there been any improvements to the audio engine since 8.5? I often get dropouts and glitches despite having a PCI sound card, ASIO drivers, and a quad-core processor, and it appears to affect the timing of tracking subtly as well.
6. Is it any more stable than in 8.5? I get a some crashes when saving, when adding track templates, crashes almost every time when exiting the app, etc.
7. Has the Matrix View or the Step Sequencer seen any improvements during X1 and X2? I'd like to use these more often, but they always felt half-finished.

1 yes
2 not sure what is being asked
3 with FX chains in the PC there are a lot of things that can be don with them.
4 Sonar can record any CC. You can change a cc to another or add a cc.
5 Yes
6 its stable
7 yes and yes improvments have been made.

John, some followups:
 
2) imagine I have an audio clip from 2:01:000 to 3:01:000, one bar long. There's a snare hit at 2:03:90 in there. I want to be able to drag the audio within the clip so that the snare hit is now at 2:03:000, but the start and end of the clip are unchanged at 2:01:000 to 3:01:000. This is available on Pro Tools and Reaper.
3) I don't know what you mean by 'the PC', but I'm specifically asking about track folders or an equivalent.
4) I know Sonar can record any CC - I need to know if it can record 1 CC and treat it as if it was 2, either by duplicating on record, or routing it in 2 directions during playback (and ideally monitoring)
6) Did you notice an improvement relative to 8.5? If you found it stable in both 8.5 and in X2, that's unlikely to help me.
 
Thanks for the other answers.
 
Question 4 reminds me of a related issue - does X2 allow you to route 1 MIDI note to 2 or more outputs yet? eg. via a drum map? On 8.5 it only allows each note to be mapped to one place.

There is a way to drag a waveform within the clip boundaries, but I can't recall exactly what it is.  I think it might even be in 8.5 as well.  Might be worth a search in the help.
 
For track folders, no, they are for organization purposes and don't act as a bus (though that would be nice).
 
I haven't used 8.5 since shortly after X1, but for me X2 feels a bit smoother than either one.   I'm pretty sure there were some audio engine enhancements outlined in both X1 and X2.  One example would inserting VST/i's while a project is playing back which I don't think 8.5 can do at all?
 
 
Edit: At least I think you can still do the waveform drag... haven't found anything on it yet myself, though I doubt it's a highly used feature

2) ALT+SHIFT+drag moves data within a clip
 

scook
2) ALT+SHIFT+drag moves data within a clip

And it works on 8.5 too! Funny how I never discovered that before. Doesn't seem to be in the help file.

Maybe mentioned in Scott's book.
 
You may want to try the X2 demo. The X3 demo probably won't be out for a while.

scook
2) ALT+SHIFT+drag moves data within a clip
 

Thanks!!  At least I know I wasn't imagining things!   Well, at least this time. 
 

scook
Maybe mentioned in Scott's book.
 
You may want to try the X2 demo. The X3 demo probably won't be out for a while.

This ^^

Why not try the demo out and see for yourself :) Only you will know if it works for you.

It can take months to truly get to grips with a product and learn everything about it - evident by the fact that I didn't know that one of the features I want is already in 8.5, which I've used for years! So it's much more efficient if people who already have that experience can give me simple answers to my questions.