My sensei was just talking about this last class. We've been doing the basics as taught in a book like Best Aikido, since they're more straightforward, sensei said. At the seminar I recently attended, I got to see a different way to do a standing kokyu-ho, several variations of the ikkyo and nikyo pin (the pin, not the way to get to it), and alternate movements for kote gaeshi.
I think it also has to do with, like said, posture and how you carry yourself off the mat. I'm not going to name names or insult or anything, but there's a guy at our dojo who's kind of stiff in his movements. He has a powerful technique most of the time, but sometimes it feels robotic when I take ukemi.
Also, there's another person generally flops around like a rag doll...and he's constantly throwing himself as nage simply by doing a technique on me. Not saying they can't do it, just that we've all got our own physical and/or mental nuances that either help or get in the way. (Like for me, I analyze myself too much and tend to stop mid-way through and start over...and it's not just an aikido thing...I did that when taking piano, and I do it with math sometimes...)