I'm on the brasilia, and I've been in some very nice icing situations. I have seen bridging a couple of times (luckily we weren't in icing for a long period of time), but it was brought on by cycling the boots too early in clear icing conditions. Not to say it happens all of the time, but I'm sure all of the stars need to be aligned for it to happen. Like Clue said, you gotta watch the tailplane icing close (just because the leading edges don't have much, doesn't mean the tail is clear too). I usually base the boot actuation off of the current accumulation. I've never have issues with airspeed decay, maybe the occasional prop imbalance (due to the stellar prop deice system *sarcasm*) but it's worked well for me. The FAA's done more tests than I have so take this info with a grain of salt.