I have the Pampers Big Kids Set, and all the parts are interchangeable, which is nice. There are a few issues though. If you use a spout with the red top (normally used with a nipple) It doesn't vent as well as the training handles, so the cup collects a lot of suction. Also, the spouts are directly attached to the lids with training handles, so when you twist the handles onto the bottle, the spout moves, so it takes awhile to work it so that the spout is centered between the handles. A few of the tops are also very difficult to twist on evenly, but not all of them. They sit awkwardly on the top, and sometimes leak, and if you tighten them too much, they pop and release, and you have to start over (which is super annoying if you've just gotten everything centered). Some of the lids are also very loose, and will fall right off the top at the slightest angle. Again, it's not all of them, just some. Once everything is in its proper place though, my 1 year old son loves them and has no problem holding them himself with the handles. Definitely not worth full price, but a decent deal at the Woot price.