Don't underestimate the clusterf**k of TBIT - the lines there can be truly abysmal, particularly if something goes wrong and you have to re-check your bags from CO at the BR desk. Last time I was through TBIT, security alone took 50 minutes. It's an overloaded armpit of a terminal and I'd not recommend cutting it close. If you need to make a real tight connection, you'd be better off in SFO at least...although the CO and BR terminals are at opposite ends, it's all indoors and the SFO int'l terminal is a breeze. You could also consider Seattle as an option if you want the new 777.