Upgrade if your hardware can handle it, but I suggest waiting till X3E which is out next month (you've waited this long... why not wait another month).

Many things in X3 are better than pre-X series. The console view, however, isn't one of them. That got ruined in X1 and 3 versions in it hasn't been fixed, so looks like we're stuck with that. 
 
I'm mostly happy with the upgrade. The included version of Melodyne is slick in how it integrates, but a bit disappointing unless you do the upgrade to Editor, so if that is attracting you, plan on shelling out a bit more on top of the upgrade price. That said the X3 producer upgrade plus the melodyne upgrade still cost less than just buying melodyne editor on it's own, which I was planning to do, so it was no-brainer territory for me really.
 
Best thing is to try the demo and see for yourself.

Go for it.  It is better than the 8 series.  The learning is not difficult in my humble opinion.   The sooner you do it and get over this little learning curve, the better.  I would not wait for the next update.
And if you are on XP, get Windows 7 or 8.
Ultimately, it comes down to whether your product will sound better.  My 8.5.3. project sound better in X3d. Not sure why and I do not care why.

Go for it!

As with most things, the more time spent in doing whatever pays off in the end.