I've been using a Polk TrackerII for about a year now, and I really like it. The scanner thing went a long way to calming down the reactionary members in my club who remember the old Kraft "dial a crash" system. (Many many years ago, Kraft had a radio that was synthesized. You could even change the channel while it was on (the TX, not the RX). So, you could turn one of these on, then turn the dial though all the channels, and clear the air in a hurry, not good)

I fly a lot of competitions, so it's handy to be able to change frequencies. I have a pile of crystals, mostly on my two main channels, but I also have a few on other channels that I could use in a pinch if needed.

It's also important to remmber with a synthesized system, that you still need to get the frequency pin (some guys seem to think it makes the pin system obsolete). There's nothing to prevent someone from turning on while you are flying and shooting you down.

Dennis, you didn't buy a polk because of the way it looks? How much time do you spend looking at your transmitter when your flying anyway? (I will admit that the Polk is a BIG transmitter, noticeably wider in the hands than most. I use a neckstrap, so the extra width is a bonus for me, but other guys don't like it's feel when holding it)

Btw, the really cool thing from Polk really is the Seeker receiver. It's a lot more innovative than the transmitter is. It works with any FM transmitter, synthesized or not, any shift any frequency (in a specific band), no dials or crystals or anything to change.