I have been using the 500R since I got my bp about 3 months ago. I'm not having any problems with it. My only complaint really is that it allows for about a 4-5 degree variation in temp. The way I have mine set, it turns on when it gets to 89* and turns off at 94*. I do have a couple small pieces of advice for you though. Make sure you have your t-stat and thermometer probe set right next to each other. You may even want to use a nylon zip tie to fasten them together by the probes. Also, you will need to monitor the temps at least daily as you may need to adjust the setting as external temps fluctuate.

Overall, my opinion is that if you have one snake, one tank or tub, it will work for you better than a rheostat. If you're planning on running a rack with multiple tubs, I would invest in one of the higher end stats...

Good luck!