It may have been the GPS signal strength rather than the mapping, but its disconcerting when you seem to go way off course randomly even though you are on the right road (luckily l tested this on a route I'm half familiar with). Obviously on roads you don't know, with the low mapping detail on the 200 you could end up chasing your tail trying to get back on course when you're not actually off it or going way way off accidentally.
I have never had this problem with my 200, 205 or 500.
Plot a route on bike hike, transfer to the unit and follow the breadcrumb trail.
I do this regularly for rides 100+ miles on unfamiliar routes. They have never taken me off course.