I got a preview invite from Wagamama's in Harvard Square and I gotta say that it was pretty disappointing. I know it's a chain restaurant, so my expectations weren't that high, but the food was seriously mediocre (the one in London is far better and a little less pricey for the quality). I had the yaki udon and it was nothing to write home about. Honestly, the Japanese food at Takemura down the block is much, much better and the Japanese kiosks at the Porter Exchange is fabulous -- I'd much rather spend my money there.
I will say, however, that the yakitori was great - good grilling and yummy sauce. Bravo! And the service was decent -- I know they're trying to work out the kinks now (hence, "preview dinner).