The 4XL is gigantic! I have a big desk (1.6m2 corner desk) and I have to move stuff around just to use my Intuos 4 L. Honestly, for you, I'd recommend an Intuos 5 M (medium). Those are big enough if you don't have a stupid large monitor.
Gigantic... *rubs hands together with glee* I don't know, everyone is always trying to make stuff either bigger and better or smaller and better... seeing as my eyesight's going and my hands are temperamental when it comes to cramping up, I think I really am on the bigger and better side of things I have plenty of room on my work station too, thankfully...
I have heard both opinions about tablets, from a friend who is a fantastic Digital Artist, and a Traditional Artist. They were good and bad opinions both. However, I honestly want to get a tablet myself. If you feel like it would help, I say definitely get it. It's worth trying, or what you could do is get one of the less expensive ones, and try that out, then improve. My friend who is a Digital Artist started with a cheaper tablet, and later was able to improve. I wish I could tell you one way or the other, but I have no idea. Let me ask my friend though, I'll bet she knows about it.
You know, I don't think she's going to get back to me, that friend that I talked about. -_- Of course, this is that same friend I drew the picture for that I have been talking about, so yeah. I'll look into this myself, too, it might help a little. Besides, I love doing research.