Thats right. They were definitely a big distributor of it when it first came out. I know a few other places offer it nowadays, but in terms of actually mapping it, Jamsport are probably up there in terms of experience.
That said, I know of a good handful of Escort owners that had it (either purchased/fitted, or purchased a car with it fitted already) who binned it off. The lack of general support and the unit itself just weren't worth the hassle.
Depending if you've bought it new (hopefully not as you would have done your research beforehand) or just inherited it, nows the time to decide wheres best spending your ££.
Edit: Just realised you said you bought 2nd hand. Still, probably should have done some reading before spending. Hopefully didn't cost you too much