A lot of this though comes down to personal choice/preference - I mean, I use massive bats (my three main ones at the moment are a pair of 3lb+ Newbery B52XLs and a blank that comes in at 3lb 4oz) but I'm not a particularly big hitter, though I am probably as good as anyone in our club on the back foot and a compulsive in going after the short ball...
...my reasons for using such big bats then? Well, for one, I'm a big lad and that does undoubtedly have something to do with it. And I used them when I was younger, fitter and more likely to drive in the air. But most of all, I have always found that light bats sort of wander off in the downswing and cause me to chip the ball up or play across straighter balls.
So, yeah, different things suit different people. I reckon a batsman using a 2lb 8 will probably middle the ball as far as the guy with the monster - the extra speed makes up for the lower mass. But the guy with the monster will mishit sixes that the smaller guy could not.