Have you seen what the side of your fridge looks like? Stainless fridges do not have stainless sides. The upper cabinet gets pulled out and is easier to reach and use. The panel gives a more finished upscale look.

Chispa, I did not want side panels for my fridge until I read that here on Houzz some time last year. So glad I found that out in advance!

definitely get the panels but I just looked at a nice LG fridge and the side matched the front. models vary....if you didn't want black fridge sides and had to use an existing opening without cabinetry panels you'd be ok finding an aesthetic looking fridge.

I have a preference for the panel and a deeper upper cabinet.

I much prefer having a panel. I don't like seeing a gap between the fridge and the wall. A panel gives a more streamlined look. Spills and crumbs can't fall off the end of the counter. A short backsplash will protect the panel from spills.

Refrigerators need room at the top for ventilation. There are various ways to provide it, but since your cabinets go all the way to the ceiling, make sure there's enough space between the top of the fridge and the cabinet above it.

Another vote for panel........