My 2 cents. Have Maytag, bottom freezer, single door ref section. Freezer section has rolling basket to give 2 levels. Ice maker a bit inconvenient, but we don't use much ice, so no big deal.
All shelves in ref section, including door shelves, are adjustable.
Hint- since most single door units are reversable, set it up to be convenient for chief cook. SWMBO is right handed, so I set it up with hinges on left. Can open door with left hand, reach in with right. No crossing hands or switching. Had to take door off to get it in the house, so only took an extra 10 minutes to change. Use in non climate controlled location- most,& key word is MOST, refrigerators are controlled by main box thermostat. Main box temp is more critical than freezer temp, 10° too cool, things freeze, 10° too warm & things spoil. Freezer temp can vary over wider range with no harmful effects. Cooling coils are in freezer section, it cools first, & cool air circulates through vents to ref section. If located in cool area, such as garage where temp is 40°, the main box is cool enough, the unit won't kick on, & freezer also warms up to 40°. Just the nature of the beast.