I bought my GPS at the beginning of 2008 - looked at either TomTom Rider or Garmin Zumo.
After looking through loads of forums, reviews etc. on the Web I decided to go for the Zumo, as the TomTom was reported to have some reliability issues. Garmin also supplied both car & bike mounts in the box. The final factor was that, apparently, the Zumo is designed as a Motorcycle system, whereas the TomTom is adapted from a car unit?
However, the Zumo has not been perfect. I have had the unit lock up on me in the car once, which was fixed by removing the battery. To do this, you need an Allen key - luckily I had one with me.
It also locked up the first time I got caught in rain on the bike. Again removing the battery re-set it OK, but the motorcycle cradle was killed by the rain. I sent it back to Garmin who replaced it for free (quickly too) but it shouldn't have happened.
In terms of using the Zumo, it is pretty straightforward. However I find the display a little jerky too - it makes it easy to miss a turning, especially if there are 2 close to each other.
Overall, I'd say it is an OK piece of kit - easy to use, and much easier to use on the move than traditional maps. I'm definitely a SatNav fan. However as far as reliability goes I am disappointed. Seems the Zumo has as many issues as the TomTom is reported to have.
I've never tried the TomTom Rider, so I don't know how well they actually perform, but at the moment I would not recommend the Zumo purely based on the problems I have had.
