Did you ever get a reply, or come to a conclusion on this? I have been using Plural Eyes for 3+ years, and it works pretty well. I edit with Premiere Pro, which is also capable of syncing to audio, but albeit a slower process than Plural Eyes.
I'm a bit baffled about Tentacle Sync, as it requires the editor to have one of the boxes to launch the Tentacle Sync software. This means I couldn't use Tentacle Sync devices when handing off files to clients that don't have that system. Do they offer a stand-alone version of the software? Seems like it would help get their market share in a big way. I have read that Tentacle Sync software doesn't support some video formats, but that may be something they can fix with updates.
I presume Tentacle Sync's time code is more reliable than syncing if you have bad audio. Other than this situation, I'm not really sure what the advantage of Tentacle Sync devices are.