In my experience, fim'ing works best for compact indicas.
Nirvana's Papaya strain is extremely compact and dense... the stems grow very close to the main stem. Growing from seed, I got one big (thick, not long) cola and a couple medium sized ones.
Its some really killer smoke, so i fim'd the 2 clones I took. They reacted very well to it.. Guess we'll see if it was worth it in a couple months.