I'd say it depends on the competition.
A competition kite is designed to do a job. For ballet/precision , and especially for pairs and teams you want a kite that behaves predictably. You may also want a set of kites (UL, std, vented) for different conditions.
For individual competition you might be prepared to use a kite that is a little less predictable but is more trickable. Again you may want different kites for different conditions.
And for a trick competition you will want a kite that you gel with and that gives you the fullest range of your repertoire of tricks and you may have to improvise as you push the envelope of your and the kites abilities.
Of course a lot of it comes own to personal preference too. But I'd say the 'easiest' kites to fly are 'near competition' kites. Full sized competition kites (eg Furys) can be a bit of a beast to fly. They will do exactly what you want, but they are undoubtedly hard work
Whereas a quantum pro (for example) is slightly smaller and definitely easier to fly, and while I have seen it used in competition (successfully), I wouldn't use it in competition or call it a competition kite. You may of course disagree