Some second-hand experience from the GPS newsgroup, Hans. The eXplorist line is very broad, competing with essentially all of the Garmin lines. The entry-level 200 is rather limited, so check carefully that it can do what you need.
I hope I am not confusing models here. Check the catalog before believing all of this (grin):
1. Battery not replaceable. You need a power outlet every day.
2. No connection to a PC. Thus no advance route preparation and no track download.
3. No external power, thus not for extended use driving to the trailhead.
4. No uploadable maps. I consider them essential for biking and hiking, as does most of the community: http://gpsinformation.us/main/gpshiking.htm
The top of the line 500 model, expected in October and priced to compete with Garmin's GPSmap60C, will not be so limited, apparently.
Now some first-hand experience with the WAAS corrections that give 3-meter accuracy. It works in the clear, but disappears with the slightest blocking of the signal. It works for me about 1/4 of the time while road biking, almost never when off road (which means amid trees here in Vermont).
There are two WAAS satellites, both in equatorial orbit, only one of which is visible in most of the US. Much further away than the GPS satellites, their signal is much weaker. My receiver is on the handlebar. When I round a curve and turn my back on the WAAS satellite low in the southeastern sky here, I see the correction drop out.