Does anyone have a reason not to consider this algorithm snake oil? e.g.:

Was it developed by a well known cryptographer? Has it been vetted by someone/some organization with reputation?

I other words, why should we trust it?

It was developed by a team lead by Mitsuru Matsui and has been subject to fairly intense analysis, although not by non-Mitsubishi people AFAIK. In any case it's not the usual snake oil. When I last talked to someone from Mitsubishi who was working on Misty I tried to convince them to make details available online, you could try something like www.melco.co.jp to see if there's anything available. Peter.