I was looking at L2 on thinkorswim for UNH and sold one share on Public. This was at 8:43 am and the bid was at 522.63. I put in a market order and it was filled at 521.86.
That seems like an unreasonable discrepancy. Combining this with their requirement to manually unselecting to not tip them for each trade (completely insane) and I think I'll be taking most or all of my money out.
My biggest draw was that they paid for options trades and had a good rate on unused cash. Those things aren't worth staying if I don't trust the company.