The 1130 has an advantage the the A/B/G antennas are built-in. It's low profile and great for mounting just above a ceiling tile. They are not however as rugged as the 1200 series. They are made of plastic (But plenum rated) and require 802.3af power (Your older 6500 modules that suppoer Cisco power will provide power to the AP, but not enough to turn on the radios).
I've been going with the 1131's for office space and 1231 (Now 1242's) for garages, warehouses, and areas that may need something a little more sturdy.
The wattage of the radios is the same as far as I recall off hand. If you're using security features, it's nice not having to put external A and b/g antennas on a 1231/42 if you only intend to use b/g.
