I think the garmin forerunner 210 is a good watch, i use it mainly for logging my runs but also has basic intervals. You can switch it from pace to show speed for the bike. For running its good for pacing against hr zones or your pace p/km of course. accuracy and reliability as good as edge 705 so far, better hr strap too.
you may also want to look at the new timex run trainer, which is fully waterproof.
if you want a watch for navigation then dont get a watch, get a cycle gps..
310xt get good reviews too
as a watch the 210 is normal enough in size and looks but will need regular charging.