I use them all the time. I have done two batches of apfelwein in them, and one for each batch of beer (to watch the process better.)
The gaskets do not need to be replaced, they are sturdy enough for carbonation, and stand up to multiple uses.
Primary 1 : (empty)
Primary 2 : (empty)
Bottled: Pumpkin Ale, Ed's Apfelwein IV
Kegged: Irish Stout, Northwest Pale Ale II
Thinking about: Rye Ale, Russian Imperial Stout
Gone: Robust Irish Porter, Ed's Apfelwein I, Ed's Apfelwein II, Northwest Pale Ale, Ed's Apfelwein III, English Brown Ale, Blanche de Chambly clone