I talked to a guy on our 675 repeater using the Motorola MSR350. He sounded okay, he was about 5 miles closer to the repeater than I was though. Little quiet, which would leave me to believe that the Motorola bubble packs are all narrowband radios. What that means, the FCC claims that 2.5 kHz deviation is equivalent to -3 dB of signal with 5 kHz deviation. Some 3rd party repeater contractors have shown the number to be equivalent to nearly -6 dB in real world tests. So using a 2W narrowband radio is equivalent to a 1W wideband radio (per the FCC) and no better than a .5W wideband radio per 3rd party testing.
Personally, I'll stick with my 4W Icom and Motorola's. As far as the BF-666/777/888 goes…some of them won't actually narrowband and none of them have Part 90 grants. The FCC has acknowledged and stated that they are not interested in pursuing people using Part 90 approved (or even older Part 90 wideband only) equipment on GMRS as long as they are using it properly within power limits and not causing harmful interference. I own a BF-888, though I haven't hooked it up to my Bird (have to find a low power slug first) I have calculated the transmitter through FSPL to be closer to 3.5W and not 4W or even 5W. I did find with the 888 that it's a 3 dB improvement if you use a $8 Motorola Jedi series UFH antenna.