I'm a long time user of the Trimble 4800 and 4700 gps systems. They've way out performed their life span but just keep right on giving me good results. I'm thinking seriously about buying the Trimble R10 but I don't want to drop $50,000 on 2 new systems. I'm planning on using the VRS network in my area but there are several spots that I won't be able to be on the VRS. Couldn't I just use the R10 and my 4700 base in the case of not being on the VRS? What will I be losing if I do this? I'm also wanting to upgrade to a newer base radio and hope that the new base radios will work with my 4700. Any thoughts would be helpful. Not sure I always get the best thoughts from my dealer.