305 or 405 or something else entirely?

is the only difference the wireless data transfer thingy

to be used for walking, running and cycling

Do you need mapping on the unit

got a 205 for £55 recently. why pay more?

mapping not really required

205 lacks a HRM, but for that price……. where from tracknicko?

I've got a forerunner 305 for running and cycling. Works great for tracking where you've been and things like pace and distance – used it for basic navigation last weekend, found a GPX route I wanted to do, put it on there and followed the black line around a 75k road loop. No faffing with maps at all, was easy enough to guess where to go at which junction to stay on the line. Not sure how well that would work on foot with it on your wrist rather than on the bars (so always pointing the same way) though.

Great bit of kit IMO. And I've not used the HRM stuff so if that doesn't interest you, just get the 205 instead.