A couple of the guys I know who flew them said that if the early models hadn't had a yoke they'd have never been able to get a decent "flick roll" out of them at all, and even then the early models still rolled fairly slow, and the faster you went the slower they rolled because you couldn't roll the yoke over as easy. The later models had a little less feel, but rolled fairly fast, faster still if you stood on the rudder, and the faster you were going the faster a late model would roll. The boosted ailerons came about because pilots complained that it was near impossible to get a good "flick roll", and that was a serious problem in combat.