I've been using Garmin products for 3 years now: the Forerunner 201 and the 305.
Bought the 305 earlier this year after a chat with Garmin sales. £285.
A few weeks ago, not long after posting yet another defence of Garmin, I started thinking about the product, and started being a bit more objective. I faced up t othe truth, that the altitude doesn't work. The calorie readings are useless. The Virtual Partner is implemented less well than on the 201. The GPS functionality and the speed of the satellite detection is not noticably different on the 305 than on previous models, yet this was the big promotional sales message. There are some annoying backward steps in design, like the battery reading no longer being visible when you start the unit, and no longer estimating the amount of battery life yet. (I've twice run out of battery in mid-long run recently. Annoying.) I'm sure there are other annoyances which I've forgotten.
Anyway, I wrote to Garmin to complain. They replied, admitting that the GPS functionality essentially didn't work. They admitted that the calorie measurement didn't work. That the VP functionality needed to be looked at.
In short, they seem to be admitting that they are marketing one thing and selling something else. When I asked permission to quote them they got rather sensitive and said no. So I can't quote them directly here, but only paraphrase them.
I really like GPS technology for running. For me it generally works well. But anyone who would willingly blow £285 (or whatever it costs these days) on an item that the manufacturer admits doesn't actually work properly, must be nuts.
By all means buy a 201 or 301 from eBay. You'll still get most of the benefits but at a fraction of the price. What you won't get is all the defective functionality.
£285? Yer 'avin' a larf Garmin.