Funny thing about irimi nage in the two versions we've been discussing (and we even did this in last Thursday's class): most will call the irimi/omote/Segal/etc version more aggressive or less gentle/less nice, etc...
But from being uke for several different folks, I can't say that it feels that way to me. It can be bell-ringing/ star-inducing or soft/gentle, and so can the tenkan/ura/ 'usual' way...depending (I think) on how fast nage lets me fall at the end.
I did notice that I am much better at taking the center initially on the 'Segal' version, probably because I am half his size, and soooo much less skilled, if I don't immediately take center it definately is going to fail dramatically. 'tenkan', on the other hand, I think I may be giving way a bit too much, and then rescuing the technique as I go along. But partners I've had (and instructors) can do either to me pretty roughly if they desire... maybe because they take the center immediately on both versions, and I go as fast as I have to to keep up with nage in the turn.
As for the speed, someone on another thread said they couldn't go fast in the turn and so moved slow, so perhaps with enough partners like that we are used to turning more slowly, but with the 'irimi' version we can move quickly, and uke is more motivated to keep up (ie, fall) with the movements of nage. I will give some belief to the 'I just can't move that quickly' statement, but not a lot. Someone that big should have fairly long legs, and can cover ground if he wants. I keep up with nages twice my size, although it makes for a pretty fast/hard landing at the end...but my motivation is I know it will be very unpleasant if I 'fall off' of nage mid-technique.
I'm not saying nage can move independently of uke, there needs to be good timing between them, but the faster uke is willing to move with nage, the more speed translated in the downward movement of uke in the end.