I never run at buffer sizes <256 (just because I don't need to so may as well save CPU cycles!) but gave 128 and 64 a whirl with the new release and...well, it works. Much better than previous versions: if I needed to, I could now run a hefty project (plug-ins and synths) with input monitoring on TH-U at a 64 buffer size if I need to, without dropouts or glitches - I've never been able to do that before.