i got a igo w2 and a igo w3 in, and to be honest, the w3 is the better of the two. however, IMO, both suffer from a case of the drips due to where the air slots were machined. there isnt much of a drip well, so if you tend to over drip slightly ( i do) it will end up just leaking out of those holes. love the size of them, but those air slots could have been better thought out.
also whats nice is, if you dont like the "ribbed for her pleasure" look of the w3, you can swap it out for the better looking w2 cap.