I never had any problems to date with bittrex and I vaguely remember having to jump through any hoops to get a enhanced account but I know 2 other people that signed up to bittrex shortly after I already had a account and they've had issues getting their account verified even after doing what was asked of them... I keep getting questions posed to me by these people on what did I do that worked for me. At least now I know that it's a actual problem not just limited to the 2 people I know... I've had similar issues with PoloniEX. I will check out BitShares.
Thanks for the useful post!!! I like it when I learn new things! :)