I have been using a D-50 and D-70 for the longest time and have always heard about timing problems with the D-70. I purchased a JV-2080 about a year ago, and have been totally amazed at the power, including the timing. I have used it with an MC-50 and have never experienced the problem as described by all the other posts. I am just now starting to integrate a computer into the setup, so I don't have any experience with timing and software sequencers, but with my MC-50, I have had fairly complex sequences and have never had a problem with timing. Perhaps I am just used to the slower responses of my older gear. But as far as I am concerned, the JV-2080 is a power house that definitely lives up to my expectations. I was involved in a CD project that used a JV-1080, JV-2080, & Akai S-2000 sampler. With this combination, all the music was composed and recorded, usually as virtual tracks exclusively. We didn't run into the timing problems as others are complaining about. I am not trying to say it doesn't exist for them, I am just saying that I have never experienced it myself. I have gotten complex sequences with the D-70 alone, so the JV-2080 was a big step up for me.