You're right... those bars are a royal mother.... to take apart. That said... the ones that have had their oil maintained and changed haven't given much trouble around here. Mine has never been apart (yet) in 20 years.
I've got a 1460 Deere with the modular Kuhn FC bar and I'm changing modules in that with more frequency that I care to... due to rocks mostly. The old GMD bar, as far as I'm concerned... was a LOT tougher. The 1327 used that bar (GMD)... but as you well know, no oil and they don't last.
Personally I'm not a fan of the shaft drive bars.