IMO, it's not a matter of "more personality" it's a question of type of personality. Fatties are more laid back than leos, often a tad bit easier to handle, but they are also more shy and a bit less active. Leos are more likely to be either aggressive or skittish than fat tails, but are also known to spend more time out in the open and be more active. And even beyond that, each animal is an individual; there are always exceptions to the rule.
Neither species is all that comfortable outside of it's environment, if you want an interactive reptile pet I suggest looking at a larger diurnal species like Blue tongued skinks or bearded dragons.