The cut-out on the Aero is larger than the cut-out on the Atola. But there is no difference in the cut-outs between the Aero gel-around & the regular --just keep in mind that gel, due to its squishy nature, will bulge out, so it may give the appearance of sloping. The gel version is definitely a more forgiving seat, you will feel that you settle into it. The regular Aero is quite firm, you don't settle into it, you perch on it. I would choose between the 2 based on firm seat vs. cushioned. If you feel the Atola was too hard on your sit-bones, you might want to try the gel-around Aero. If the firmness of the Atola was ok, then go with the regular.

I started with the gel-around on my trainer & rode through the winter that way. I was comfortable enough in the spring to put one on my road bike & was able to do metric centuries on it. Later, when I felt I needed a firmer seat, I made the switch to the regular. I just had to work my way up to it.

PS -- bicyclebuys.com had the gel version for $45!

PPS--the nose on the gel-around is very nicely padded, too, extra bonus points for comfort when riding in the drops.