Cartridge reliability

Chakster, how do you know that any manufacturer's compliance rating is at 10 or 100 Hz. It usually does not say. Certainly the math is done at 10 Hz  RF = 159 divided by the square root of Mass X Compliance. So it makes more sense to report it at 10 Hz. You assume that just because a cartridge comes from Japan that it is automatically reported at 100 Hz. 
I do not use the math. I stick to lighter tonearms than add mass as needed by actually measuring the resonance frequency. The variables are poorly controlled so to be accurate there is no other way. Go ahead and put an XV-1t in a 12 gram arm and tell us what happens.  If there are any owners of XV-1t's out there tell us what arm you use it in. I do not own a Dynavector. But, the arms I have seen the XV-1t in would squash a cartridge with a compliance of 20 um/mN at 10 Hz, unless they have been poorly matched. I suppose stranger things have happened. 
Moving magnet cartridges tend to be more compliant than moving coil cartridges because their moving mass tends to be lower. I have an Audio Technica VM95ML It's compliance is listed as 7 um/mH at 100Hz. That would make it 14 um/mN at 10 Hz. This AT is less compliant than the Dynavector? It is less compliant than most MM cartridges probably because it is a dual magnet design. More mass requires a higher compliance to keep the resonance peak of the cartridge up out of the audio band. Obviously it would help if the manufacturers would specify specifically how the compliance was measured.  

I used a Lyra Clavis for decades, without problems...I finally changed it, thinking it couldn't possibly still working 100%, not because it had failed, only then to damage it with my poor handling!!

Chakster, how do you know that any manufacturer’s compliance rating is at 10 or 100 Hz. It usually does not say. Certainly the math is done at 10 Hz RF = 159 divided by the square root of Mass X Compliance. So it makes more sense to report it at 10 Hz. You assume that just because a cartridge comes from Japan that it is automatically reported at 100 Hz.

Yes, and basically this all you need to know. You will never find a Japanese cartridge designer who will use 10Hz, maybe there are an exception, but 99,9% of the Japanese designers always use 100Hz.

Keep it as a cultural thing, it’s JAPAN, not USA

I do not own a Dynavector.

I owned 3 different Dynavector LOMC and over 60 different Japanese cartridges (new and old) of all types. So I have some personal experience.

Moving magnet cartridges tend to be more compliant than moving coil cartridges because their moving mass tends to be lower. I have an Audio Technica VM95ML It’s compliance is listed as 7 um/mH at 100Hz. That would make it 14 um/mN at 10 Hz. This AT is less compliant than the Dynavector?

Some MM (MP) carts like Nagaoka are low compliance, cheap Ortofon Concorde and OM are also very low compliance cartridges and they are MM.

Yes. Dynavector KARAT is higher compliance than some modern MM.

Obviously it would help if the manufacturers would specify specifically how the compliance was measured.

All manufacturers (except for Japanese) are using 10Hz to measure Dynamic compliance (All American and European manufacturers).

Japan is always 100Hz, this is rule №1

Dynavector compliance is just like ZYX (12-15cu @ 100Hz). And when I asked ZYX via US distributor it was confirmed. They think it’s not good to measure a cartridge using 10Hz, so they are using 100Hz instead for safety reason! It was like a quest for me 7 years ago to figure out how and why it's 100Hz and how to convert it back to 10Hz.  

The Defects that the OP has referred to are to be found in Cartridges.
Not all Cartridges will have suffered from the conditions being referred to, but there is always a possibility that  there are Few Individuals who have had a unsatisfactory experience with a Cartridge, when it comes to it maintaining a Good Condition.

What matters from that point on,
is whether it was a experience when the Cartridge was a relatively New Model with little use, or whether it was a Long Term owned Cartridge with a long life of usage behind it.

The next thing that matters is how the Cartridge Owner felt they had been dealt with when reporting their discovered defect to a Supplier.

If the OP were to make a list of Cartridges that have their attention ?

A Google Search should show up Cartridge Owners experiences with possible reporting on any reliability issues to be seen.
In some cases, there will be a clear description of how the
Cartridge Owner felt about how they were supported when reporting their experience back to a supplier.

I have adopted this method to learn about a few Cartridge Brands.

The van den Hul cartridges are known for their hight degree of variable quality. The inespensive one are usally pretty good. The expensive ones it's a crap shoot. If you get a good one they are execptional. However, if you get one that is not good they are horrible (collasped cantilever. stylus falling off the cantilever,motor assembly not straight on the half body) and gobs of glue all over the place.