Boring characters
 

This is a common problem with superheros, and all "shared" properties. The only FF comics really worth the read are issues 100-102 of the original run. The first 40 of these have a sort of goofy fun to them. They don't take themesleves at all seriously, From 40-102 the comic is more serious and continuity oriented, and is a ton of fun, if you can get past the dated references and the cheesy dialogue- keeping in mind that they were written for 8 year old boys helps a lot.

My fondest memories of the FF universe are the ones where the scope is really really big. Like saving the galaxy big rather than saving the city or even the planet. I never had much feeling for the characters; they were Marvel analogues to the flat scientist-heroes from pulp science fiction of the time.