I am definitely more of an 808 fan but on the surface I would agree that the 909 is a better machine in almost every way. The snare is great. The kick is nice and punchy, but while offering more knobs it's less adjustable. I think if the 909 offered the long kick the 808 has it would have a much larger place in more types of music. For me what kills the 909 is the cymbals and hi hats. They are definitely great for 120-140bpm music but if you slow the tempo to 80-90bpm the machine sounds disjointed and doesn't "flow". When the aria videos came out for the tr-8 the original engineer said that if he were building a new sampled drum machine today he would use the same hi hats and cymbal. I just happen to disagree with that decision. I wish they would have made the 909 100% analog or at least had an option for analog or samples. I think the 909 samples sound really bad.

If dry, I agree (unless you're making dub-techno, in which case the 808 BD is king). But with cunning use of compression and EQ you can do plenty with an 808 BD that would allow it to be used in techno.