Elizabeth has it exactly right. All the tube forums extoll the button. If you clicked on the Roger Ebert blog about feeding tubes, he had pictures of the gtube he uses but he also had embedded a You Tube video of a young man changing his own button.

The buttons do have to be "measured" unlike the tube. They appear to be much more convenient but the devil is in the details. The button has an anti-reflux valve in it so you need to use a special connector that "locks and twists open" the valve. No matter how big your button or tube is, the valve is only about 10 to 12 FR. You cannot use the mickey button without that special connector.
I wanted one at first due to all the raves, but the doctors at my CCC dissuaded me for two reasons: (1) I grind up 6 different pills a day to put down my feeding tube and they felt they would clog the anti reflux valve (2) they claim they have to replace the button every three months due to reflux valve failure while the tube lasts 6 months.
If you go to the button, please keep us posted. Almost all the children use only the button as otherwise they end up pulling out the tube. On my gtube boards, the adults all use a G tube and not a button based on their doctors recommendations with one exception. I like the extra security of being able to use the tube without the extensions if I had to since it just has a little plastic closure like on a beach ball so there is really nothing to clog and the few times pieces of pill stuck, you can see it in the plastic and easily flush it. But I have been seriously thinking of the button
If you try it, please keep us posted.
Charm