I currently own...
...both of the "small" big Glocks: the 10mm Auto G29 and the .45 ACP G30. Both are surprisingly mild shooters, considering their considerable "horsepower-to-weight ratio". The G29 is (with all but the hairiest 10mm loads) no worse than an Officer's-size 1911 style in .45, and the G30 is milder than most conventional 9mm's of similar size. Opinions on the reasons for this vary, with the low Glock bore axis, the broad, recoil-distributing backstrap, and the alleged shock-absorbing 'flex' of the polymer frame all being credited to some degree. Regardless of why, the results are the same; despite looking like fearsome handfulls on paper, these are both pleasant pistols to shoot.