I'm in the process of opening an account with them. I will try to update in a few weeks.
There's a guy on this forum who goes by Speedracer, and he uses them. He seems to think highly of them.
Also, they offer free Real Tick software. I don't know whether they will take it away if you don't execute enough trades--probably not, because they charge $250/mo for fewer than 200 trades. Since they have their own proprietary software, that fee is probably for Real Tick, which is $250/mo.
Anyway, I think that's a pretty good deal, Real Tick plus their software free after 200 trades. Normally I would say that's quite a few trades to get free software, but charging per share instead of by ticket changes things. 200 trades go by quickly if you scale into and/or out of positions.
BTW, it's not necessary to post the same thread twice. Plenty of people will see the thread.