I would rate FCP better than Premiere in almost every respect, and (at least for me) it had a very short learning curve (NLE is NLE, regardless of who makes it). There was, however, one snag... Dissolves.
Dissolves are fairly intuitive in Premiere, but in FCP they STILL, after several months, make absolutely no sense to me. Every time I have to do a dissolve, it involves seemingly irreproducible voodoo to kludge it into place.
So expect it to be maybe a little sticky with regards to that, but you should otherwise experience smooth sailing. I personally would never go back to Premiere unless I was forced to.
P.S. The manual IS super fat, and informative. The online help ain't too shabby either.