I'm thinking about using a BMX flip flop hub for my next single speed. At half the price (ebay) of "regular" flip flop hubs, I think this might be a fairly economical way of getting an SS bike. I just wanted to know if there are any large disadvantages that I'm overlooking. Here are the ones I know about:

1) Narrow axle. I think my frame (an old Raleigh mixte) has narrow stays so I should be okay... if not, I can always use spacers, right?
2) Fixed sprocket is smaller. I plan on using only the freewheel side for now (which should be the same size, right?). And if I wanted to add a fixed sprocket, I'd just need a BMX specific one, right?

Can you guys/gals think of other disadvantages?