I just bought one of these for DS and I'm not impressed! According to the instructions, you have to press the base of the spout to release the liquid, meaning that you'd have to be pressing the spout as your child is drinking out of it. Is that right?! If you don't press the spout it is really dificult to get anything out but are you really supposed to have to hold it all the time?
LOL the child presses it as they close their mouth around the spout, not you!
If your DS is quite little still he may take a little while to get the hang of it. If he prefers something that the liquid just pours out of rather than having to suck/squeeze for the drink then try a tommee tippee plastic beaker with the flip up hard spout for a bit first.
Oooooh! It's just the way that the instructions are worded makes it sound like you are supposed to do it. DS is 1 and I'm trying to get him to take milk from a cup. He has loads of those TT flip up cups for water and juice but won't have milk out of them so I thought I'd try something more bottle-like.