I gotta second what gilchaser posted.
I looked at getting a plastic boat for small water, and was surprised at how heavy many of them were. I have an alumacraft 1436LT, which, as the name indicates, is lighter than the regular 14'. The hull only weighs 130# and my 9.8 ob weighs about 60 lbs, so the 14' boat and 9.8 merc with couple gallons of gas is about 200#. Most plastic boats I've looked at weigh 125 - 155 lbs for 10 - 12' models, and are limited to 6hp outboards.
My aluminum boat is much more versatile than a plastic boat would have been for my use. I can take the motor off in about a min and have a 14' fishing rig that weighs about the same as many 16-17' canoes, or leave the motor on and head out on the main lake to a crappie hole or duck blind.
A 12' aluminum boat fits easily in the back of a pickup and can be loaded/unloaded easily by two people, or by yourself with a little more effort. I have a cheap trailer for my 14', and it was worth every penny. So, in short, I am much happier with my aluminum boat than I would have been with plastic.
"They bitin' up river on that topwater"