I got mine from Maplins too, never did manage to find any bargains on the mount itself, although the as you discovered, Quest units can be found.
There are quite a few people who don't like the Garmin mount.. apparently the terminals are prone to corroding (inside the mount, not on the outside). Mine has only been on the bike for 6 months so no problems yet, but I'm keeping an eye on it.
As far as the Q1 itself goes, I've had mine for about 18 months and it suits me fine. I've found the best way to use it is to do all the routing in Mapsource and download, not type stuff into the Quest directly (that's where the lack of a touch-screen shows up). I tend to pre-plan my routes and download, then use the Quest with the auto-recalculate turned off. When travelling abroad I usually do a route for each day and also save 2 copies of each route into the unit. The reason I do that is that I don't usually use the default calculated route , but tend to customise the route after the system calculates it. (First time i did that, I did one copy of each day, played around with one of the routes while I was away and cocked it up.. no pc to download it again and I was knackered.. doh!). I've never managed to get any decent volume with my Autocom (I wear earplugs) which is a bit of a pain, but on all my trips it has still got me right to the door of every location bar one (in France, it told me I was 'there' at one hotel, when I was still half a mile away) and on another ocassion started trying to send me the wrong way around roundabouts. Overall though, I'm dead impressed and wouldn't be without it (don't think many Q2 users are saying that though, I'm glad I got the older version)