OverBridge sync is okay, for me. But not great.
It's subtle, but noticeable. I like having sync as tight as it can be.
For really tight sync I have to dial it in via Ableton's MIDI Preferences page (MIDI Clock Sync Delay). I test by recording audio (maybe a simple kick and hat pattern) and seeing if it lines up on Ableton's grid. Zoom in as far as I can go to check waveform against grid. Nudge the Delay until it lines up really really close. So far, best results are always from this sync method.
But I think ultimately it's just one of those things, it all depends on the individual's setup/computer/etc. Also, style of music. Some people can notice, some can't. Some care, some don't.