I do not know other's experience on the numbered series and offset cubs but mine is in the range of several thousand hours, mostly mowing, with both the numbered series and the offset cubs when I was younger and had a real job. I had an Fcub long before I had a numbered series but I mowed with a lawn tractor rather than the Fcub since I remembered my experience when I was younger. No cute names for my tractors, they are there for me to do work and the faster I can finish the work, the happier I am. I do mostly mowing and a little pulling, plowing, etc. For me there is no comparison, the numbered series is what I want for what I do with it. If I was a farmer or pretend farmer and I needed something that size, I may consider an offset cub. The lack of a Fcub's independent PTO make mowing an unhappy experience.
I do not know what constitutes a junk PTO but my experience is the 154/185 had good reliable shafts and PTO clutches. I can take the clutch off and have it apart in 30 minutes. It is simple, standard bearings, and the company that made the clutch is still in business. My tracked loader has a similar camlock design for the steering clutches and does my Yazoo commercial mower. The only failure I had was a bad bearing that was a standard size and replacement from a bearing dealer was around $15 dollars. I have never had to adjust the PTO since then, no real maintanence other than greasing. The bimetal disks are fairly thick and should last just about forever. I expect most of the clutches "needing" rebuilt really just needed adjustment. The independent PTO clutch on the 154/185 is more work than that on a Fcub simply because the Fcub does not have an independent PTO!
One bearing failure in thousands of hours, thats pretty good. I have not purchased a 184 because of the electric PTO clutch, they may be reliable but I can fix the camlock clutch if needed. The electric clutch, not sure how repairable it is.
I am not aware there are any first postulates in engineering that state a clutch must be mounted to the engine flywheel, if so, all the cars in my driveway got it wrong. There is nothing strange about the 154/185 clutch, still has a pressure plate, disc, splines, pilot bearing etc... also has a ball bearing throwout bearing not a piece of graphite. No failures in the thousands of hours I spent on the numbered series. I can take the clutch out in 30 minutes and reinstall in 30 minutes all while sitting on a concrete block, no need to split, no splitting stand, quick and easy.
I can use my car to cultivate with but I don't think it would do very well, not built to cultivate. The numbered series is good for several things and great at other things. Cultivating is not one of them. If you want to cultivate then get something higher then a loboy. One size does not fit all.
There are some disadvantages to a numbered series. Less were made so less parts are available, some are more expensive like a radiator, some are less expensive that with an offset cub. All numbered series have an exposed clutch and splines, dust and grime may affect the wearing of the clutch splines and shaft. The numbered series are narrower which may be a problem for hilly areas. The frame may crack but can be easily welded. Less implements available. The tractors themselves are harder to find.
I do not know the mean time between failures for either the PTO or main clutch and I doubt anyone on the board knows and experiences may cloud a person's view but to answer BigBill's question, Yes, the numbered series get an undeserved bad rap. My 3 have been great, I wish I could say the same for all my Fcubs.