smidsy, the two in your link, is what my mate has , cost him about £90 a year ago, no real problems, was SiRF II chipset, nothing wrong with that,

But the newer SiRF III like jims is meant to be so much better at recieving signals

mine was a £45 cheepy SiRF II which works well, but im going to renew my whole set up, and will be getting the latest SiRF III reciever