I started watching the anime so I can pick this up in a few days (JP version). It's not bad, but half of that is probably because I used to play MMOs. The anime does a good job of invoking that feeling on being in an MMO world despite the cultural differences.
The only things I don't really like so far are Kirito's OPness and the camera work (and Asuna's walking animation in the opening is weird.) You'll be watching some sad or tragic moment where the female character is expressing feeling and the camera will be centered squarely on her ass. "Hey everyone! Don't mind what this character is talking about - just look at her ass!"
Game sounds fun and I'll probably scoop it up.
As for Bamco localizations, I don't want to say too much but their localizations (with a few exceptions - notably the Tales series) are generally bad. I believe they outsource the work to a third party and I've personally done damage control on shoddy translations in the past only to have all of my changes undone when the next draft rolls around. It's extremely frustrating. There are few localization companies that can produce truly natural sounding translations for games, but they are increasing. The place I work at was looking for translators recently and some of the applicants were shockingly bad. I think out of about 15 or so applicants, only 2 were really qualified to take the job.
From what I've seen, I'd probably say that Atlus and Square have the best in-house localization teams - with Square getting the nod. I've been a fan of Atlus for a while, but I think they can get carried away with the memes at times. Square's work on FFXIV is fantastic (from what I've seen) and I'm always impressed with how they can untangle those (almost needlessly) complex storylines into some comprehensible. I respect both teams a lot, but if I had to compare them I'd probably say that Square takes something that is overly convoluted and makes it presentable. The Persona titles, especially P3 and P4, already have a great script and the Atlus team manages to keep most of that in their localizations despite the cultural differences between Japan and "the West."
I've been curious about Xseed and their work for a while, but I usually end up buying Ys locally here so I haven't had a chance to read it.
* I think Platinum might make the list, but I haven't had a chance to play the localized ports yet.