Considering an uprade, but some questions...

I have been a long time user of Cakewalk products - going back to pre-sonar days.  I am considering an upgrade to X3, but am wondering how some of my older hardware will get along. 
 
I have a 3 GHz Core 2 Duo CPU with 4 Gb RAM. (circa 2008)
A MOTU 2408 (last version) interface
A Mackie Control (original MIDI version), an extender, and MOTU MIDI interface.
 
I have some questions:
 
Will my old hardware work with the new version of the software?
 
Is anyone using a MOTU 2408 successfully with X3?  I know drivers are important.
 
What's the state of Mackie Control support for X3?
 
What's the best OS for X3?  My current "music" boot partition has XP on it.  But I could upgrade to Win 8 without a lot of trouble.
 
If anyone has experience with some of this older stuff, I would appreciate your advice. 

I use the original MCU & XT with X3. Apart from lack of access and control of the prochannel and a few minor issues it works well.
 
I posted a whole list of problems here. Most of them are very minor and you'd probably not notice them unless you go looking for them. It certainly doesn't stop me using it though and apart from the Prochannel issue I hardly, if ever notice the others.
 
The biggest change you'll find is the move from 8.5 to the X series. They are quite different in layout etc. but IMHO in a good way. Approach it with an open mind and don't try to use it like it is 8.5 and you'll find it a very slick, quick to work in program. I have been using Sonar since V2. When I switched to X1 I just "clicked" with it and now wonder how on earth I managed to stick with previous versions for so long.
 
Why not try the demo first? That will answer most of your questions. However as noynekker has pointed out XP is not supported so you'll definitely need to upgrade OS. Windows 7 works fine here and so far I have seen no need to upgrade to Windows 8, although I do have a license for it.
 
I guess I'll get around to that one day.
 
HTH