IB accepts PFOF for their "Lite" TWS, which is thereby free. The older "Pro" TWS -- which is directed or SMART-routed, has long audited as delivering better trades than the market, by far.
Im running TOS and IB at the same time and IB has much tighter markets on spreads,they show the bid / offer and size..TOS does not. What bugs me is if A spread is offered mid market,IB shows it where TOS does not. I believe IB also reroutes orders if a better offer or bid comes in,TOS does not..
There are alot of things I like about TOS.but trading spreads is not one of them..
