Cherry switch life -- clarification?

[Wordhopscotch]

When people talk about the life of the Cherry switches being 50 million keystrokes (or 20; I thought I read the browns were 20 million), are they referring to the switches' general ability to still depress and generate characters, or do they just mean the clicky/tactile "notch" you feel when you press the key halfway? I ask because my AT board's keys are definitely softer than the PS/2 from age -- there's not quite that halfway click anymore -- but they still work.

The problem is that they're also feeling heavier/harder to press. I don't know if that's just because I don't have the clearly tactile halfway point anymore, or if that's a sign the switches are giving out.  
I was lucky to find this for a work/library spare, and am hoping it has more life in it so I won't have to feel like I'm bottoming out the keys 4 hours a day. (Some of it, of course, might just be grit or dust, but I don't know how much cleaning would do if the switches are really wearing out. For people who have cleaned older keyboards, did you notice much difference in the keys after?) I don't know if refurbishment includes being able to fit new switches, but that would be a bit much anyway.

[itlnstln]

I think the keyswitch life refers to how long the switch will work as designed until the functionality changes.  So, in the case of Cherry blacks, this probably means until it cannot generate characters, or a spring/housing breaks, etc. (i.e. complete failure).  For Cherry browns and blues, this would also include the tactile feel.  I would imagine after 20 million keystrokes, these switches might lose their tactility but still be perfectly functional switches (feeling similar to blacks).  Complete failure would probably occur around 50 million + keystrokes just like the black switches.  Of course, they may last much longer than this.  The bigger question is, will you be using the same kb in 50 million keystrokes?

[graywolf]

I imagine they are talking about "mean time before total failure", that is until it is unrepairable. The thing you have to know about those numbers is that they pull them out of a hat. They mean nothing in reguard to a particular keyboard, and probably little about the entire production run. Sometimes they actually build the ones with a bigger number better, sometimes they just charge more for it. BTW, the situation is the same with any product with spec's like that, not just keyboards.

[Korbin]

My guess is going to to be the same as itlnstln's.

The only difference between the brown, black and blue switches on cherry's website appears to be the spring tension and the clicking mechanism yet black switches are rated at the 50 mill mark and the brown and the blue switches are rated at 20 mill.

[karlito]

I duno if im just crazy or what but there seems to be a "break" in period for brown cherry key switches.

I bought a filco FKB104M/EB and used it for a few months and then i got a tenkeyless filco w/ browns and the keys were noticeably stiffer so I stored books on it at night for a week.

duno if anyone else has noticed the "break in" phenominon but I would definetly say that the springs most certainly wear out.

[Korbin]

I duno if im just crazy or what but there seems to be a "break" in period for brown cherry key switches.

I bought a filco FKB104M/EB and used it for a few months and then i got a tenkeyless filco w/ browns and the keys were noticeably stiffer so I stored books on it at night for a week.

duno if anyone else has noticed the "break in" phenominon but I would definetly say that the springs most certainly wear out.

Yep. I noticed the same thing. I noticed it more with my board with cherry blacks before I noticed it with my filco browns (perhaps because it's a stiffer spring inside of them).