The biggest difference is that the AMP adjusted to Open, Neutral and Closed and the AMP Cell has MyFly Technology, which gives you numerous loft options. The colors are different, too.
I had the AMP Offset last season. I hit the Cell, in both Offset and Regular, yesterday. The Cell Offset doesn't actually look offset to me, not at all like last years' AMP. If it didn't say Offset on it I would have thought it was a regular bonded/glued driver. I believe the shafts are different between old and new models but to me they felt like they had pretty similar playing characteristics. I found the Cell to fly the ball high, just like the AMP did. Sound seemed pretty similar to me, too. And maybe I'm nuts but the head on the Cell looked a little bigger to me.
