How difficult a racquet is to use depends on the shot you're trying to hit. For instance, I have a lot of trouble hitting high smashes with my PS 85 (with a lot of lead on the hoop), but hitting them with a Prince Precision 730 (longbody Graphite II) was easy. Yet, I find the PS less demanding than the Prince overall, because more of my shots land in the court, go where I expect them to, etc. When it comes to producing power and slice, the Prince has the edge, because it's stiffer and has a less dense string pattern. Everything has a trade-off.
However, the people here who try to say that no racquet is too demanding overall are wrong, given the current tennis environment. Certainly, if 70 sqin racquets were the only legal ones, then a 70 sqin racquet would not be too demanding. Given that the current head size restriction is much bigger, a player with a 70 sqin frame is going to be at a disadvantage against a player with a larger racquet. There is a point of diminishing returns when it comes to the angles and control a small racquet offers. I have played and won matches with a Wilson Ultra II standard head size, but it IS more demanding than a PS 85, period.
Given all the variables in the current tennis environment, I'd say a racquet that's in the middle/average of every spec is probably the one for a beginner to pick. Middle stiffness. Middle head size. Middle weight. Middle balance point. Middle beam width. Etc. This isn't going to yield the optimal racquet for most players, but it will at least make it likely for a player to choose one that's manageable.