Now, I don't know TR1, but this is what just about every fan and "expert" does.
Either way, Champ Bailey had a "bad" year this year b/c the Broncos got NO pressure on the QB. Our DL had a historically pathetic showing in 06 and that directly affected our secondary play. Taylor has a fault of trying to win the game himself and he got burnt when he tried to jump routes. Normally, the pressure should have helped him out and forced the QB to throw it but it wasn't there.
Either way, Taylor was a good player in 05 as well. He pretty much carried the defense all the way to the divisional round (TD return against the Eagles, shutting down Glenn and TO both Cowboys games [not to mention blowing up Crayton on a play that should have been a fumble], causing a fumble that led to a defensive TD, that key 4th down stop in AZ to seal the win and those are just off the top of my head). I remember he also won two jump balls against Randy Moss as well, and you can probably count on one hand the number of players in the league that can do that.
07, of course, we'll never know. However, consider that he led the league in INTs, was easily playing the best as a safety and was completely shutting down the long pass. If we didn't lead the league in passes over 20 yards allowed (I believe one), we were top 3.
In response to whether he was a game-changer, he most definitely was. You can easily name 5-6 games he changed with his play, every year. Easily was the most catalytic player on the Skins.