but I'm very skeptic.  I've looked at the description and most of the NEW things for X3 are plugins.
 
what is there in X3 that I don't already have in X2 that would be worth a hundred bucks?
 
I'm cereal here.  no Buffoonery!

I was very skepitcal about the colour thing but the way they have implemented colours for tracks associated to busses is really rather good.
 
ARA and Melodyne integration is a big step forward, if you need it.

yeah, but I don't need Melodyne.  I already own Editor. 
 
how is ARA integrated?  I missed that part.  I already have Finale with Garritan and ARA there.  how does having ARA in Sonar help me?
 
color customizations would be nice, but I'm not willing to pay $100 for them.

Beagle
yeah, but I don't need Melodyne.  I already own Editor. 
 
how is ARA integrated?  I missed that part.  I already have Finale with Garritan and ARA there.  how does having ARA in Sonar help me?

The integration is the cool part. If you have Editor it just becomes "part of Sonar" and very easy to use. I previously owned Essentials but upgraded after getting X3 and seeing how the intigration works.

You get Addictive Drums.

Comping is different.
 
Some say better, others say not so.
 
Craig Anderton says you need to learn the new method(s) and not assume that it is the same as before.
 

You will get some new bugs. None of them show stoppers, just a few more niggles.
 
Best of all, you get to go from install right to X3e (skipping a, b, c & d).
 

Integration with Gobbler (online backup)
 

I wasn't really happy with x2, I tried the x3 demo and decided to buy it because it works much better on my system.
I really like the fly-out eq and siince i didn't have a lot of vst's, the nomad vst's are most welcome. Try before you buy, I would say. Also it was really cheap to upgrade ; )
 
Rik

I'm also with X2 and am thinking of getting this upgrade.......the plugins + the overall stability of X3 is my driving force. I think it's worth the $99 fee and may not need to upgrade for awhile (X4? ). 
I suppose all I need now is a Soundcloud account.