[Petrushka]

You can't tell me one and even larger one of these isn't going to cause some Q factor issues. This (the Truvativ) is designed for gravity riders though, where pure pedaling efficiency and fluidity is not at value. Same goes for durability not being as much of an issue. This needs to take rock blows, not miles of wear. I read this product as for commuters and people who put in a lot of miles around town:

http://mtobikes.com/wp-content/truvativ-hammerschmidt-detail...

And yes, the durability is entirely speculative, but, especially coming from a new company (as opposed to HammerSchmidt, which was 100 or so years old when SRAM, of which Truvativ is a brand bought them), I'd have serious doubts they'll put a top quality product out at the start.