The FlatWave is certainly easier to mount than an HD8200U. However, it is far less directional and therefor leaves you open to a higher chance of having trouble with multipath interference, co-channel interference and adjacent channel interference.
Some tuners are better at dealing with marginal signal quality than others, as your experience illustrates. The solution may seem to lie with the selection of tuner, but I submit that the problem starts at the antenna.
My personal experience with the HDHR tuners has been very good. They are occasionally beat by my Vizio tuner but not by much.
http://forum.tvfool.com/showthread.php?t=820