For the record: I almost always watch subtitled anime. I appreciate the Japanese voice acting a bit more. Though the US versions may have better sound/effects, I'm generally unimpressed by the acting. One or two characters may be good, but the supporting actors sound like they were taken off a cosplay stage in Dallas somewhere.
A note about lip-syching I've read on the Net (somewhere...). Western markets are often over-critical about timing and whether the character looks like they're saying what is heard. In contrast, Japanese audiences (or just directors?) aren't that bothered by inexact timing. I don't know if the end result is more frustrating for Western dubbers or not.