The buffer in a portable CD player is dealing with a different issue than the 990 is - the CD player knows exactly what audio format it is dealing with (PCM that it converts to analog; players of this type would not support DTS CD's) and is only concerned with getting jostled and getting the laser knocked off track briefly. In a portable player that is at risk for such jostling, the player has the buffer and then reads ahead of what is being passed to the output. The 990, on the other hand, is trying to determine if the incoming bitstream signal is PCM, Dolby Digital, Dolby Digital EX, DTS, or DTS-ES. Starting to pass audio with the wrong processing applied would produce a really nasty noise (and would risk potentially damaging speakers) so the unit has to keep quiet while it determines what it is working with. Buffering the signal and starting it once the format is determined would leave the audio out of sync with any associated video, so all the unit can do is hurry to figure out what the format is.

It may be possible for a firmware update to improve the signal acquisition time, but at some point you run into the limits of the hardware's ability to react. We'll see what the future brings, but in the meanwhile I do feel it's worth giving the 990 credit for making a significant improvement in this department over its predecessor (the 990's delay is probably on the order of 20% of the 950's delay).