I think you'd be surprised at how low commissions in futures can go for professional traders. It all depends on what you bring to the table. Let's say you use TT, host your own gateways, run your own lines, etc. etc., deal directly with clearing firms, and do big volume, you can get commish rates down to less than a nickel. Basically, all you use the clearing firm for is clearing. Of course exchange fess are seperate and vary according to your individual membership level.
Do you do enough volume to justify the monthly expenses for the savings in commissions?
If your just trading like 50rt/day or less just stick with IB, transact, velocity, or any of the numerous introducing brokers and keep overhead low.
TOS costs about 7 bucks a round trip
the execution platform is simple and easy to use
if your need is critical their tech support is pretty good
I use them because the execution platform and real time quotes --- 144 tick on ym --- are free if you keep a brokerage account
they do not have the ability to feed data to a spreadsheet - so I am looking for another system that can specifically do that ---- but I've been happy with TOS since I started trading in January