Fixed. Anyone else is just pretending. I ride 100+ miles a week on mine, mainly commuting. Now riding 48:16 (or 48:15 on lighter wheels) but it's not too hilly where I live. Geared for 19 mph (cadence = speed x 4.5). The standard 42:16 you will see recommended is better for hillier terrain (cadence = speed x 5), but I felt held back on the flat.
Depending on terrain, rides of 40 miles should be fine, even with downhills. My longest day is a 43 mile commute each way including the Col du Northolt. Which is a grind. With twin panniers.
Geared is for training, races and sportives when I want to keep up. But I still ride a 19 mph chain gang on fixed.
Oh and the pompino is heavy. I'd look for a Langster for lightness. Or a Kona Paddy Waggon for loveliness.