I'm looking for advice regarding which of these two mowers is the better
one (giving equal weight to best to actually use and most reliable).

One is a Cub Cadet 6.5 HP 21" Cut Self-Propelled Mower, Model
12A-997A712. It has a Kawasaki motor.

Are Kawasaki motors as reliable as Honda's?

You can see it he
http://www.lowes.com/lkn?action=prod...70-12A-997A712
if link wraps:
http://makeashorterlink.com/?I22922F18

The other is a Husqvarna 5.5 HP 21" Self-Propelled Mower, Model 55R21HV.
It has a Honda motor.

http://www.lowes.com/lkn?action=prod...-41798-55R21HV
or if link wraps:
http://makeashorterlink.com/?O3B816F18

The yard to be mowed is medium sized, and is almost flat. There is a
slight grade toward the street, just enough for drainage.

Last, is there a better mower than either of these two in this price range
($500 or less)?

--
Tony Sivori