Well you can switch between SS and geared for £15... Which is about the price of a cheap chain tensioner and you (presumably) have the advantage of not having something to get knocked off or damaged.
Also 135mm spacing means you can use normal road wheels with a spacer, or discs.
I'm not really sure if there are any disadvantages... maybe getting the placement righ if you're using discs?
Well you can switch between SS and geared for £15... Which is about the price of a cheap chain tensioner and you (presumably) have the advantage of not having something to get knocked off or damaged.
Also 135mm spacing means you can use normal road wheels with a spacer, or discs.
I'm not really sure if there are any disadvantages... maybe getting the placement righ if you're using discs?