Some people complain about that, other people like it. I personally don't like it because it limits you to having to carry around a bunch of staves. Of course, at the same time if you're using staves you probably are going to max out on them anyway. I didn't play a force on PSU though, so I could tell you.
If you can deal with how old PSO is (See: +10 years) I would definitely recommend it. It's a game you can pick up and play easily, with plenty of in depth building of characters. Certain episodes might give you troubles as certain classes (i.e. Episode II gives Forces problems, while Episode IV gives Rangers problems), but it's pretty easy to get around that. I personally enjoy it still and would recommend it to anyone over 13, mostly because they'll probably have lived in the time of the Dreamcast (R.I.P.).