Because of their remit and focus, I doubt you'll find anyone better at indoor CQB and Hostage Rescue than the HRT guys. I've dealt with a few FBI folks over the years. The SWAT guys and the HRT guys were notable for their humility and willingness to interact with other LE, frankly. And willingness to talk experience, tactics and equipment stuff.
Of course, I've also met the "other" FBI. The stuffy, arrogant yahoo's that make you shake your head in wonder that they don't get themselves killed going to their car in the morning, they're so oblivious.
The leadership class is who I have a problem with.....but I can say that about virtually every LE agency in the country at this point. With notable exceptions, this is a group of people whose incompetence, venality, and careerist ambition pose an actual threat to public safety. Change my mind.