The time/speed/distance relationship is so very much different in what we fly in part 121 ops that it takes some adjustments to get back in to a GA airplane and do OK. Approach speeds are uncomfortably slow and the tendency is to flare way too high. I had a NW A320 Captain actually get the stall warning horn in a 172 on short final, fortunately in that case he flared so high that it wasn't an issue to talk him through the correction. The smaller RJs and turboprops make an almost perfect transition into amphib seaplane flying though... flare is just right, still seems awfully slow though.