Although variable kits come with a lot of problems (ie, screws, paint scratches, difficulty building process, joints becoming loose over time, etc) I'm still a sucker for variable kits.
For me, its all about obtaining a "perfect variable" copy of what it was like in the anime. So for me, although theyre not the greatest as a "pure model" just for making, coloring, and displaying but I love variable models pretty much for the engineering of it. I know as soon as I finish making one of my SHE kits, I would just look at it in awe by the way it reminds me of the anime and how someone actually made it into a physical object.
So in the end, its just a different type of eye candy for me. Models tend to be the "omg, its so real looking / you have mad painting skills" kind of eye candy and variable models are more of the "omg, its variable and transforms just like how it did in the anime" eyecandy. Thats the way I see it...