stronger hit, better flavor, more vapor. Downside is you can exceed the wicking time on the CE2 if you are a heavy user (regular and MAP tanks I use are 2.4-2.5 ohm... higher end of LR and work great IMHO) and battery life can be reduced a little.
Are they ever going to make a CE2 in a 1.5 ohm? I've tried the 2.4's and it's just not as much kick as I like on the 3.7v and that's all I use.