Interesting.
I notice it says its using OpenStreetMap based maps - from looking at the photos, it just seems to be standard Mapnik images. Seems rather strange, wouldn't it would make more sense to use some sort of vector format maps?
There are a few other rivals for Garmin anyway, eg Globablsat or Holux make a few outdoor/training GPS devices. And think Decathlon have had a few own brand things as well. Though I don't know if any of them are any good, or easily available in the UK.