I bought a second hand Trek 4700 about 18 months ago to try out a bit of off-roading as I was getting a bit bored of road riding and fancied a bit of variety. Anyway, the bug has bit and I am loving it. So I am now looking for a better steed (another hardtail). I like Treks, and I have decided on an 8-series. I just can't decide between an 8000 and an 8500. I will be looking to buy second hand again (probably ebay or forums), if that has any bearing on it. Looking to spend no more than £1200-ish. Opinions please.