Hello, didn't the review already compare both devices?
It's now a personal decision if you favor those couple of positive aspects and the larger built-in storage.
If those aspects doesn't matter, then the Tab 7.7 is a fine choice.
I own the Tab 7.7 and I did think about about waiting for the AT270, but I know it being new and unavailable at the point of my decision making process, it's not worth the extra cost for my needs (new stuff are never affordable).
If you think about it, Tab 7.7 was also priced close to S$800 when it was new. But it's now in the market for quite a while and that is its advantage - a mature product that is no longer in the limelight and is overshadowed by the Tab 2 products. Thus the Tab 7.7 has become a very good buy with its updated firmware and current price.
If you need a more premium 7.7-inch tablet, the choice is clear that it's the Toshiba unit.
After sales and support is something we've no idea about and we'll leave that to other members to comment upon. Everyone has a different experience and viewpoint.
If only more reviewers do comparison tests to confirm it.