also a bit late here but just thought Id add my bit:
the bottles are great and i think do help with colic.
the teats are by far the softest 9and therefore easiest for a BF baby to get used to) I've found
however, the bottles are very leaky, even with the little disc inserted to stop spillage, so they have ti be kept upright at all times in nappy bag etc. This is very annoying.
with washing up, I've always just bunged all the bits in the dishwasher and they come out fine.
Finally, don't go and buy loads as regardless of everyone else's views, you don't know what your baby will think! They are expensive. I'd get just one, see how you go, and then send DH/DP out to get some more later.
Re the muslin squares, John lewis ones are the nicest I've found. Nice and soft, and a good size. I got some cheaper ones but my DS who is now 3 uses his muslins as a comforter and says the non-john-lewis ones are "too scratchy, mummy". Bles his little heart.