“FCP can do anything that Avid can.”
A gross generalization, of course, but holds a lot of truth.
What’s grey about a line like that is, while the two ‘systems’ can achieve many of the same things, they often have a different way of going about it.
And that’s usually the part that frustrates a user switching from one to the other.
Some important differences that I’ve found, and I hope others will add to the list so that you can investigate the relevance to your needs of the differences between the two ‘systems’, include:
The way they handle the relationship between clips and mediafiles. (including the offline/online approach you mentioned)
Information available during digitising and outputting.
Also important, these days, to understand that Final Cut Pro is not an application you can buy. FCP Studio Pro is the product, and, as is the Apple approach to most of its products these days, contains a suite of applications. So check that any comparisons are between apples and apples.
Note, too, much of the promises made by sales people about software products or ‘systems’, depends upon using the latest, fastest, best and most expensive versions of hardware.
I don’t know if there is one (if there isn’t, then that’s a sign in itself) but it would be great if someone could point you (us) to a comparison between the systems as you mentioned.
DISCLAIMER: In case there’s any question about it, I’m not taking sides, here, for either Apple or Avid!