I've had the beta versions including the "consumer preview" version installed on a PC. The only thing I can say is "yuck". I won't be upgrading my production systems to Win 8 for the forseeable future. I will install it on my "test" system as I do part-time PC support and need it as I know at least one client that is going to upgrade to it.
Microsoft seems to have "off" Operating Systems, one will be good, the next not so good, the next good, etc. I suspect Win 8 will be one of the "off" operating systems. I could go back further (my first dealings with Microsoft was DOS 3.0), but Win 98 was not so good, Win 98SE was good, Win ME not so good, Win XP good, Vista not so good, Win 7 good.