I like the unit overall. I have had so much fun with it this past weekend.
The Explorist GC does show street maps. However, it does not show you turn by turn directions how to get there. I have found this makes caching a bit more challenging. Please don't try to use this unit while driving to find a cache. Yes, I would suggest using your car GPS to get you to the general area.
It helped me to cache in an area I was familiar with first so I could get used to operating it.
I hope you enjoy yours as much as I am mine