Well, after using Meguiars, Auto Glym and Mothers leather cleaner and conditioner.
Meguiars - quite a greasy feel
Auto Glym - had to apply a few layers, was smooth after 3rd layer
Mothers - wasn't to bad, but felt a bit dry
They were all tested on my MK5 Golf R32.
The Chemical guys was fast, effective and no greasy residue.
Estimate time would be from wash to final buff off the wax; 6-7hours with half hour break.