I've been learning Amiga 3d rendering software this past year and have been really enjoying it. I bought Aladdin4d and it's very powerful and runs well on the lastest Amiga OS (with RTG, etc). The interface is a little "clinical" I find. I've also been learning Lightwave 5.0 on the Amiga. It's much more intuitive I find -- the interface is friendlier and I like the way keyframes are set up.
I've had Imagine on disk for a long time, but never had a manual for it - so I could never get my head around the workflow. I've love to buy a manual if anyone has one for sale (just PM me). I think the version I have was the latest one released on the coverdisk.