All the bats I have owned till now have had between 9-18 grains.
My way of picking a bat is - (1) pick-up and balance, (2) performance, (3) looks - clan and evenly spaced grains with no or minor blemishes/heartwood and (4) Price
In terms of performance I have found the number of grains do not make much difference, except that the ones with tighter grains open-up a bit faster - peak and fade away faster.
Comparing 2 bats from the same source (one of the best bat makers in the UK), one had 9 grains and the other had 15 grains, there was no difference in the performance, which goes on to prove for me that pressing is the key.
I have never had a bat with less than 9 grains so cannot comment on bats with broader grains, but have seen some old GNs and Newbery's are my club with 5-7 grains which hit the bat a long way and make a very good sound when the ball is middled.