Starkeeper,
The 540 is still a fairly decent keyboard. The 550 only has a few things on it.. Other than that they're pretty much the same keyboard. I'd agree that if you can afford it, skip over the 550 and get the PSR-1000.... We're in the same boat, I'd love to be able to afford the PSR-1000 myself.. Just having an internal sequencer and working tweeters would be a huge improvment over the PSR-550. Now that I think about it, one of the main reasons the drum kits on the 540 and the 550 are so dry and bland is because you really don't have any high end to them.. The tweeters don't work on either model, so the sound is no where near as crisp. I remember when I bought the PSR-540, shortley after that I played the PSR-640 in a store and was shocked at the difference in sound between the 2 boards.. Granted the 640 had more megs, but a lot of that good sound came from much better speakers.. Maybe I should send an email to Yamaha and suggest they put a half decent speaker system on the 550. Hell the Casio WK-1600/1800 have better speakers.. Boy how I miss the 15 watt system the MZ-2000 had..