Big truck is safer in an accident. I drove F100/150s for 35 years, all with 4.9L inline six and love that engine, but fuel mileage is poor. I just got a used Ranger 4-banger last Dec and love it, 25 mpg consistently. Feels real nice and sporty being so small. A blast to drive and easy to fit into parking spots. All my F100/150 and Ranger are manual transmission. Always drain out the wimpy ATF from the manual tranny and fill with Redline MTL or a Syncromesh fluid. ATF is too thin.
The Ranger certainly is a very usefull and capable small truck. Guess it all depends on need, if need is the determining factor. I finally got a '72 F250 351C V8 last year and love her but she is not practical and gives me 5mpg but that was want rather than need. I know a Ranger would serve me better but.....
Do NOT drain out the ATF and replace it with something else. The trans is designed to have ATF to lubricate it properly, its a given that you replace it every 30,000 - 50,000 miles. The heavier gear oils do not lubricate the transmissions internals properly. The sychros get the worst of it, but the bearings don't care for it much either. I have sent eh damage that the heavier oils do to these transmissions. If it is specced to run Mercon ATF, or MerconV, use the specified fluid and nothing else. Replace it at the manufacturer recommended intervals and the trans will last and shift like it is supposed to. My Dad's '96 2.3L Ranger has 363,000 miles on it currently, and it has no shifting issues using the manufacturer specced fluid (Mercon).
Ford dealer service rep approved my running a heavier lube in my M5OD on the '95 F150.
I know you can burn up a splash lubed bearing if too thick but syncromesh approx 30 wt and it is the heavy gear lubes that were the problem. I tried M1 ATF I tried Redline ATF, but it was not until I ran the slightly thicker Redline MTL (not the heavier MT90) that the truck finally shifted nicely. Always shifted notchy until the MTL and that was installed around 150,000 miles, but guess what, with all those miles on the tranny, with the MTL I could shift it as fast as that huge shift lever would let me and never a grind or complaint out of that tranny. Ran that over 40,000 miles and still shifting beautifully.
Way back prob in the 1980s Chrysler speced manual trannies with ATF and there was a "gear rattle" problem. Chrysler's cure? thicker fluid, no more gear rattle.