The Sippy Cup Cunundrum

We have started the weaning process in the Stone home.  If I did not have to go back to work in mid-August, we would not be at this point yet.  I am totally content not to pay for the liquid nourishment that my daughter needs.  However, I will be returning to work, so we need to get her to a place where she is not dependent on me, at least during business hours.  All that being said, we are learning about the world of sippy cups.  I first purchased this one by Munchkin:

I bought it because it was the cheapest one I could find (that looked decent), figuring we could try it first and upgrade later.  This works great for the YoBaby yogurt smoothies that Aubrey likes.  It is a very simple design: no weird valve parts inside to worry about, just the rubber nipple part, the handle-and-ring part, and the cup itself.  And, remarkably, it doesn't leak.

Recently, I decided we definitely were ready to have more than one cup in the house, especially with the weaning process on the horizon, so I went in search of more cups.  The only complaint that I had about the Munchkin cup was that there was no cover or cap for travel purposes.  I found this style cup from Avent:

The ones I bought have a flip cap instead of this style cap, but the rest is the same.  I thought it would be the best option for the diaper bag.  I liked the idea of the flip cap so there would not be a removable cap to lose.  We have used them several times now, and the only down side is the valve inside:

It's hard to see in this picture, but on the under side of the sippy part, there is a clear disc that attaches to the little peg thing in the center.  Number one, you have to take it off for cleaning... and it's clear, so it is invisible in the bottom of a kitchen sink full of soapy water (and fits in the sink drain if you forget it before pulling the plug).  Number two, while it does its job of keeping the cup from leaking (sort of), it also prevents the liquid in the cup from flowing nicely when baby sucks on it.  When the baby sucks on it, it does this weird straw-with-a-hole-in-it thing where too much air gets in.  (Yes, I tried it out to see for myself.)  And while baby is drinking, it tends to leak out the air hole!  Way too complicated for a not-so-impressive result.  And, more importantly, Aubrey gets frustrated with it.

So I plan to stock up on the Munchkin ones, and hopefully I can find some with the same top plus a cap.  If anyone reading this has found another cup that works for your little one, please comment letting me know which one and why you like it.