The reasons why people seem to dislike them have been covered above, but I think the full bikes are absurdly expensive for the spec you get. I’m not saying that I don’t understand why, it’s just a fact. When I was looking to change bikes, I would have had to buy an SE at around £3k to get a similar spec to what I had.
However, I test rode one against a few others (Stumpy FSR, Trek EX, Heckler, Marin Wolf Ridge, Yeti ASR5) back to back on the same trails and the Five was by far the most exciting and had the best riding position for me. The others felt pretty dead, especially the Stumpy.
In the end I bought the frame only brand new as I was so impressed and built it up with my existing parts. Still not cheap at £1250! But then they are built in the UK with the higher associated costs. Many of the US brands are cheaper as they’re often built in Asia.
I may be alone, but I actually think it’s a good looking bike since it got the flared and bent top tube. Before that it was pretty gopping and I’d never have wanted one. The simplicity of the single swing arm and the way all the angles work together just looks ‘right’ somehow. I also like the ‘industrial’ look of it. You can see exactly how it’s been put together.
It’s not the lightest of frames but never rides like it’s heavy, though mine is quite an XC/light build (XC717/Hope XC hubs etc!). I have no idea what it actually weighs as a full build.
In a nutshell, I love mine and would only change it for the sake of it, but I can totally get why there is a dislike of them. I certainly couldn’t justify the cost these days.