The M5OD actually IS better than many trannies offered in similar sized pickups. The one in the Nissan runs through bearings unless you run a quart over the specified amount of fluid, and you have to add that extra quart at the shifter. Nissan doesn't tell you that, and silently raised the fill plug on later years (1998+) without mentioning it, or even having a service bulletin to dealers to add extra lube to the trucks that were still under warranty at the time. As a result, if you don't know this, and you run a lot of steep hills with a load, you'll kill the tranny within a very short time. One trip fully loaded up a mountain will do it. We all know jeeps come with weak (relatively speaking) axles so what good is a strong tranny if your axles snap? And what about most of them only having a 3 speed auto!? Rangers have the most durable drivetrain overall, because all the other vehicles have a significant weak point. Chevies - Engine and Suspension, Nissan - Tranny, Jeep - Axles and Electronics, Toyota - Frame and the 2.7l 4-cyl in them has lots of issues.
Yes, I know this from personal experience. I've owned just about every Ranger sized truck/SUV or something on the same chassis (or a roommate did and I had to fix it every time), and the Rangers are the only ones I'll keep around. I went through manifold studs and engine electronics in my 2.5 Wrangler like candy but the 4 popper didn't have the nuggets to break an axle at least, the Toyota has a ridiculous engine design which made me have to do cold oil changes if I wanted to get the filter off and the starters don't last and are a pain to change and THEN my truck broke in two - before the recall, don't get me started on my '96 s-10 - that would take too long, my Nissan Hardbody had PLASTIC DAMNED TIMING CHAIN GUIDES THAT WORE OUT AT 40k MILES and the tranny oil issue - and it got 16mpg from a 2.4. Yeah, some of these seem like small issues, especially on the Nissan, but they are a huge pain in the butt to deal with.
I will admit I did a budget build on a '97 Hardbody for my old roommate and fixed the mentioned issues, lifted it, added a header and full exhaust, ect. and it's still a great little wheeler, but it's easier to do with a Ranger and the Ranger will get better fuel mileage and have what feels like twice the power every time, which doesn't make a lick of sense. I still won't recommend one to anyone.
Oh, I forgot to mention, the whole time I had all these other trucks with issues - I still kept my first vehicle ever kicking around and road legal, a '90 Ranger 4x4, and ended up driving it most of the time simply because I was always repairing my main daily driver, and the old beater Ranger was as reliable as the tide. Only parts I ever replaced was parts I bent from doing absolutely retarded, retarded mean things to that truck - like snagging brake lines on the trail, hitting a rock with the tranny crossmember at 30mph (drove home with the rear driveshaft chewing a hole in the cab), snapping a leaf spring because I loaded the bed to the brim with rock and hit a nasty pothole (truck STILL made it back on it's own on the overloads with just the main leaf left) and a few bent shocks here and there. Fords are the only trucks that don't seem... fragile.