Friends....
I'm interested only in two factors: durability and reliability. Of the two, Glock 27 vs mp.40c, which do you think has a higher level of durability...able fire 5000 per year for the next 10 years?
And of course... which one is more reliable. Thanks
Durability: the ability to withstand wear, pressure, or damage.
They are even. Both will need replacement parts for wear items (recoil spring, extractor, firing pin, etc.) when you are talking lifetime round counts. One machine is not inferior to another when it comes to the reasonable replacement of wear items. For instance, have you ever shot a subcompact with a worn out recoil spring? The limiting factor is not the machine, it is the shooter. Many people talk about "battered slides" but when a subcompact in 40S&W has a worn out recoil spring, you will know because it batters the shooter. At the point where the shooter looks at the handgun and really doesn't care to shoot it due to noticeable recoil is the point when a new recoil spring is required. It has not lost durability due to the necessary replacement of a wear item.
Reliability: the quality of being trustworthy or of performing consistently well.
They are also even. Both are polymer framed, striker fired handguns from reputable manufacturers. Trying to compare two well made products ends up coming down to minutiae like magazine cost, "aftermarket support," and other nebulous decision factors because people have to split hairs to declare (or rationalize) a "best" when comparing very good products.
The problem I see with the question is that it attempts to make a decision point based on very narrow criteria. I wouldn't consider either the most important criteria among equivalent products. That would be - hand fitment. Does the handgun fit your hand? Is the grip comfortable and is the sight alignment natural?
The typical responses to the reliability and durability in the context of a lifetime round count will either be from people's opinions based on a manufacturer's customer service or from people who don't shoot the round counts referenced because if a person shoots the round counts referenced, both handguns will require periodic service.