Well, the Streetpilot III worked fairly well in the Leeds city centre - but it didn't recognise the post code, but found the full address when that was put in. However, it does choose some weird routes. Going from Uttoxeter to Leeds all the way up the M1 as far as Barnsley it wanted me to turn round and go back south - it had another route in mind up through the hills and across Manchester!
I ignored it and went up the M1 past Sheffield, once past Barnsley it agreed and put me on the M1, where I already was. From there on it guided me reasonably weel, but you do need to get used to the directions and what it means at bear offs, rather than proper junctions. Proper junctions are fine, but where there are several rounds leading off it is a bit ambiguous in how it describes what you need to do.
The next day I was going to kent and Sussex, it didn't like that at all and hadn't logged the new address. It did eventually when I stopped for breakfast and I rejigged the address and put it in again. It might just be me getting used to it, which I am.
I must find out how much map I have in it. I wouldn't know where to look to find the card, so no idea how big a card I have or what maps are in, but it is supposed to have the whole of Europe in it. Will go and have a play in minute when I have an hour to clean it from yesterday.