I started with iMovie, but soon realised i needed more, so moved over to FCPX and although still. learning, i am finding that it does meet all my requirements, also there are number of creators out there who are more than happy to teach new tricks and better ways to do certain 'tricks'. I'm a big fan of Arthur Moore and have learnt so much from him. I also believe that iMovie was a great gateway to FCPX, but I still have a long way to go, last but not least, knowing how to do a particular cut / transition / effect and actually doing it are two very different things, don't give up, never stop learning.