Comparing manual trans options - variables other than gear ratios?

It's easier to replace certain parts
Are you talking about ease of assembly? Then I agree with you; BUT in all honesty, stuffing the small bearing guts into the box is not that big a deal.
If you're talking about installing the back bearings , Ok I sorta agree with you.
But if you are talking about procuring parts; what am I missing? My small-bearing A833 hasn't needed new parts since I installed it in 2004.