I use both padded and unpadded.
With a newborn, I like the padded rails but not the shoulder pad. The padding in the rails helped to support the head better. The unpadded edge of the sling had to go over her head in order for her to have support. Once she could hold her head up, it wasn't as much of an issue. I didn't like the padded shoulder because I didn't need it with such a light baby and it felt bulky. But I would still have needed it to spread out, so padding was OK.
With my first DD, I actually switched back to the NoJo when she was 2 because I wanted the padding sometimes. It wasn't as adjustable, that is true, but sometimes I just wanted to basically strap her against my side and the NoJo was good for that. The rings grip better than the thin metal ones on my Maya (I still have the thin rings--the thick might be better). The other good thing was that sometimes when I had her legs hanging out, the padding would be better against the back of her thigh than the edge of the unpadded sling.
But I ended up just using the Maya once she was over 3.
With my 6 month old, I use them both frequently, and I've started using my Baby Trekker also.