I'm also not a fan of mini pumps, but not because of valve breakage. It's just too slow to get decent inflation with one, and I carry a full length frame fit pump on my road and commuter bikes. I consider CO2 inflators too expensive and enviromentally unfriendly. (it's not the gas, which is either volcanic in origin or distilled from the air, it's the cartridge and entire process)

Any pump use shouldn't lead to valve breakage, so here's a few hints. Most of the folks I see breaking valves do so because they are not effectively bracing the business end of the pump as they work the other end.

First, even though the thumb lock makes it unnecessary, grip the pump head and tire together in one hand, so the pump is braced (through your hand) to the wheel, and doesn't stress the valve with each stroke. This takes a bit of practice, but comes naturally to those who've used push-on heads without thumb locks. Also do not brace the bike too rigidly, leave room for the wheel to move or actually support the bike by the wheel while pumping. With a bit of practice you'll never break a valve again while pumping, even if you use a hand pump daily.