I’ve had the Ditto X4 for a few months. I got it after watching @Aldo’s videos because I also enjoy playing guitar with my synth and sampler. I wanted MIDI sync, thinking I could trigger it from my M:S or OP-Z. Neither of them works that well for it, so I’m just sending the MIDI clock sync from my M:S and triggering the Ditto with my foot.
I’ve experienced all the issues people here have mentioned. A few lockups. It seems to miss MIDI triggers (part of why it didn’t work all that well with my OP-Z). And it’s weird about start/stop when it already has loops stored. Sometimes when I start the M:S sequencer the Ditto starts the loop where it left off, rather than from the beginning.
All that said, it’s still fine. If I were taking it on stage I might be a little nervous about relying on it. But an occasional glitch at home is no big deal.