I too am a fan of the Avent Isis. I have used it with both my boys and plan to use it this time round as well. I have also lent it to a friend. The parts are still in good working order but you can definately buy replacement parts if need be (sister in law had to replace part for hers, and got an improved version so was definately worth replacing). Really easy to express especially when 'let down' and loved how it attaches to all the bottles or has a freezer bag store option which I used often.
Enough rambling - love it love it love it.