Robotic pool cleaner. Any navigate tanning ledge?

Newbie. In-ground plaster pool. Looking at robotic cleaners. Pool specs:
18'x36'
Depth 3' to 4.6'
2 skimmers
Main drain
4x160 Inteliflo
Autocover

Pool was just plastered 2 weeks ago. Pool builder suggested the Dolphin and had it in his bid. After now researching, I'm leary of the Dolphin (primarily due to difficulty / impossibility of finding parts / obtaining repair service). I'm primarily considering the Blue Diamond. Other viable alternatives include Aquabot Bravo (probably out due to cost and similar reviews to Blue Diamond) and Aquabot Turbo "Model G".

A few concerns:
We have a "bench step" and tanning ledge. I can attach photos and diagram when I'm approved for the forum.
Trees

Questions:
Will ANY robotic cleaner (or even other type of pool cleaner) be able to navigate the bench step / tanning ledge. Associated measurements:
Tanning ledge is 6" deep.
Don't remember exact dimensions of the bench step, but ballpark:
Vertical wall leading from step to tanning ledge = approximately 12" tall
Vertical wall leading from pool bottom to bench = approximately 9" in the center and 12-16" on the edges.
I can obtain accurate measurements if necessary.

As photos will show, we have many trees near the pool. Trees aren't on top of pool, but we will be battling leaves. We have 4 small children and thus wanted an autocover. We plan on having the pool cover closed when not being used for saftey. This will decrease leaf burden, but not eliminate it.

How does Blue Diamond do with leaves? Any robotic cleaner do better with leaves?

Thanks in advance for the help. Chad