I’ll be using a GPSMAP 60 csx while I’m in Prague and was wonderng if they are worth downloading even though they are free. I think I would want the CZ map rather than a TOPO map mainly to show me where the caches will be and how to get to them but are they detailed enough to be of use?
I doubt about it. In the very centre of Prague is it good enough, but outskirt parts of Prague are just for rough guess, without streets. No miracle, but better than nothing, I guess. European Metro Guide v5 or European City Select v6 or higher is much better for geocaching in Prague, of course if You have some :-).
I would say, that metroguide does quite well in major cities and western part of Czech, but eastern part and Moravia is much better covered in the free map.