There is a reason that the 2 and 4 ohm readings are not listed. According to Jim Tanner from Bryston it has to do with Canadian UL regulations as this amp can draw more than 20 amps from the wall into low impedence loads. Since this is the max allowed from a common 115v circuit it would not be able to meet UL approval. I have had some time listening to a 28b and there is no bottom lacking in my experience. It's an old audiophile axiom that power has to double as impedence is halved but this is contingent on how tightly regulated the power supply is. Even if the 28b only put out 1000 watts into 4 ohms that's quite a bit and how often is this going to be inadequate in a home setting. Specs don't always tell the whole story.
Bryston 28B SST
For those of you who have heard the new Bryston 28B SSTs - are they as good as the reviews I have read? From reading these reviews I almost get the impression they can drive any speaker from a highly efficient horn to an inefficient planar speaker and sound great. Are they a major leap from the 14B or 7B or just a bit better?