.even kernels are stable kernels that have been released into the normal world.
.odd kernels are bleeding edge ones that are still heavy beta. Take your chances with 'em. They may work wonderfully, they may kill the system (but you could always just boot back into a stable kernel)
On the other topic:
# Linksys WUSB11 v2.6 - this is completely different hardware than v2.6 see AT76C503A for Linux drivers (much worse than for v2.5 at the moment). Since it is At76C503A - the sensitivity is weak, output power - 32mW 32mW is taken from datasheet. However we ere told that there are two other lines of WUSB11 v2.6 - with 40mW and 80mW output power. No idea how to distinguish between them.