There is a quick reply going to be added in phpBB 3.0.6. It might be best to wait until after then before adding one as their might be problems upgrading.
Don't use Prime Quick Reply, there have been a few boards hacked that were using it. Also, the built in one in phpBB 3.0.6 is very bad. You have to set it in every forum you create, and it ONLY has the quick reply field, no bbcode or smiley section.
If i were you, i would use "Advanced Quick Reply". Best one out.
I write all of my posts in Quick Reply. I can't believe that phpBB3 is so backward that it doesn't have quick reply yet... They have it on ProBoards even, lol.
I always find it best to not add mods just before a update in a area where phpBB are making alot of changes to. I know that this forum is a pain in the backside updating as i know 3 mods which i will definitely have to remove.
BTW, i wasn't for 1 minute suggesting using the default phpBB3.0.6 quick reply. That is terrible.