Is there any more information on the "plan on changing the implementation in 1.10 to be more like jQuery Mobile"? Under which point on the roadmap does that belong to?
Whatever will change for that, I cannot imagine that it wouldn't require the same line-height changes as well. Form styling will always require some "special attendance".
I wouldn't recommend removing the line-height completely, because that would cause trouble with a different line-height in any container (e.g. in body) and it will look inconsistent again. Instead I would set
.ui-button .ui-button-text as well as
.ui-button to have
line-height: normal;. That will not guarantee that it will look consistent across browsers (because "normal" is defined differently in some browsers), but it will guarantee that the three types of buttons are consistent among themselves (which I find much more important).
Apart from that, Firefox also needs border and padding reset for
input.ui-button::-moz-focus-inner as well, not just the already existing
I tested in all major Windows, Mac, Linux, Android and iOS browsers. Before those three fixes the buttons were only consistent on iOS and different in all others. After the changes the consistency is fixed everywhere, except in IE7, and in Chrome the input button is 1px too short.
As PR 576 was rejected, I won't provide another PR. But if anyone is interested, my changes are here: http://pastebin.com/ZR1vwVHi