Re: Back Roll Exterior?
This is the reason for back rolling. Rough textured surfaces don't accept sprayed coatings too well, the coating tends to pool on the high points of the surface. Back rolling collects that surface pooling and forces it down into the crevices, minimizing shadows and such. Now, an experienced painter can minimize shadowing and surface pooling by applying the paint in a particular manner, in many cases eliminating the need for back rolling.
To try to help you narrow your choices, if all things were equal I'd go with the company that is offering the back rolling. Because this company's bid is higher than what would seem to be your preferred contractor, then I would ask for references from both companies that have done to jobs similar to yours that you could go and inspect personally. From those inspections I would choose the better workmanship.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!