Right. Much hunting later and I've found out the following:
1) Garmin class roads by speed limit, which means that they often think an unclassified road is just as speedy as an A or B road. Not good for me as I often end up needing to travel to places in the middle of nowhere in the dark. 2) Tomtom one or whatever replaces it is what I'll be getting. And then when I want new maps, I'll flog it and buy a new sat nav, as it seems map updates cost so much cash there's no sense bothering with them. 3) Handsfree stuff on sat navs apparently doesn't work well.