Just to throw my two cents in. I have a Megellan Crossover 2500T and i recently ordered the PN-20 and have made my 50 caches with it this weekend working side by side with the crossover. I let my non technical wife use the PN-20 so she can see why i spent the money. While i love my Crossover the support from magellan sucks bad. The PN-20 I had figured out within a couple of hours. The documentation was easy and straightforward....they have information on how to use it for Geocaching and what to do with it.
The 2nd day I used the PN-20. I found this unit great to work with. The search button pulling up the nearest caches to me was a pleasant treat. The compass is dead on and on top of that it seems to do really well when rolling up on buildings that obstruct sat view and still keeps you on course....
I have enjoyed the unit and it will be my primary. Then if magellan fixes its stop tracking issue i will have two great units to use.
Oh and you can navigate to the cache directly or by using the roads then wanders you in the field. I thought that was a nice feature. Others might have it but i would not know.