I went with 3. Nope I don't regret it, it fits well with trooper. I haven't had any problems with getting datacrons so far.
I do regret going 3 on my smuggler, because it looks like he is wearing gear a couple sizes too small...lol
I agree. I have a level 29 Vanguard and 20 BH merc. Heat just seems so much more fluid/easy to manage. I don't really have ammo problems, unless I pull to many champ mobs.