I'm looking at getting a red dot to use on a Ruger 22/45 pistol with a Tactical Solutions upper. I have a Fast Fire on another gun that I like, but was curious how the Doctor compares to it since they are a similar price. I really don't want to spend any more money than those, the RMR is a little to expensive to justify for the .22 pistol. I'm looking at $210 for the Fast Fire, $240 for the Doctor and also noticed that CDNN has Trijicon 8-MOA red dot for $149 (page 107 on the catalog). Any suggestions would be appreciated.