Not a necessity if you live in th QCs, but living in Cedar Rapids and in winter it absolutely is if you are headed to Chicago and have a 60 or 70. With an 85 you have to drive cross country up to Rockford, refill, and then down to Chicago - no 380/80/88 route. Adding Iowa city won't help - too close to CR. Although coming home it will give you a little extra comfort in an 85 if you try to do 88/80/380 home...Of course, I don't know much of anything about this, but wanting to travel in the area, I would guess Davenport is not a "very necessary" place for a SC. One can get from IA City to Madison, Rockford, Peru SCs pretty easily, but I certainly understand your wanting one in the Quad Cities.
Just got the location as:
North Ridge Shopping Center
4064 E 53rd St
I believe it is Bettendorf. My daughter lives there.