I've started using TDAmeritrade for futures.
Commissions are slightly higher (around $2.50 + exchange fees per side). The data feed is free (IB charged around $100/month for data for NYBOT issues such as TF).
Setting up an order using the thinkorswim desktop platform is a bit clunkier than with TWS; it involves bringing up the main window, which can be made no smaller than around 1100x500 with all trade form fields visible . (If anyone knows of a way to get rid of that 300-pixel-wide left side panel, please let me know.)
TDA currently doesn't allow trading futures options in IRA accounts. I'm still using IB for those.
I'm using IB for charts. While TOS offers a terrific set of technical indicators, all I really need is a chart that can show bid, ask, and trades simultaneously, which apparently can't be done on TOS (displaying last, bid, ask, and mark are all mutually exclusive).