First of all, the few reviews I have noticed here complaining that the case is not a good fit for the Xoom are either misinformed, or they have not used their brain when fitting it.
The trick to getting this case to fit snugly around your Xoom is to insert the left-hand side (with the volume controls) into the case first, then gradually raise the lips of the top and bottom of the gel case around the Xoom until you reach the other side. A little finesse on the corners will quickly avoid what I've come to call "undertuck" (where the lip tucks under around the corners), and before you know it... one snug fit around your beloved Xoom.
The case does indeed have a rubbery feel to it, which certainly improves the grip.
The elevation it provides between the camera lense and whatever surface you place your Xoom on can provide much-needed protection against scratches (which, of course, would diminish the picture quality)
Now for the part most people don't realize...
HOW TO FIT YOUR XOOM (WITH THE GEL CASE FITTED) INTO THE OFFICIAL DOCK
This really couldn't be more simple...
All you need to do is remove the interchangeable plastic plate (designed to allow you to choose a plate suited to your preferred tilt angle), and your Gel-case fitted Xoom will fit perfectly on the dock.
Obviously you should note that, with the plastic plate removed, the white dot indicating alignment with your Xoom is no longer available, so it does make alignment a little more tricky, but a small price to pay if you wish to dock it whilst in the case.
Of course, this case is remarkably easy to fit and remove, so it is not entirely necessary to want to dock with the case fitted. The one benefit of having the case fitted whilst docked is that, should you wish to quickly remove your Xoom from the dock and take it with you, you don't need to spend the extra ~30 seconds refitting the case.
This is an essential purchase for all Xoom owners, in my humble opinion.