Is there usually a dramatic difference between $5k and $10k cartridges ?

Thank you @dwette that is the answer I was looking for. No speculation on my setup but confirming that the different/better experience with quality mono cart with my type of music. I will buy the Miyajima, or other good mono cart, then try it on my existing system. If that works, then add second quality tonearm. Expensive but fun hobby...It is great to find some that actually have made greater investments and sharing their experience. 

@luis223344 What’s nice about my setup is I have the exact mono counterpart to my stereo cartridge (Lyra Atlas: SL + Mono), both on identical tonearms on the same turntable. Both also run through the same phono-stage.

I’ve been able to really see what a true mono cartridge brings to the table, i.e. comparing Atlas SL with mono button engaged vs the Atlas Mono. Some mono records almost sound stereo with the depth of soundstage the mono cartridge adds, and they play so quiet since the mono cartridge ignores the noise of the vertical grooves.

I think it’s worth it if you have a collection of mono records you play often enough.

Many thanks @dwette I have been asking this question a few times on blogs, and you are the first one to have the perfect setup for proper A/B testing. Maybe I should not thank you as you sent me down the expensive rabbit whole... 

It's my pleasure to show you how to make wallets defy gravity and levitate. 

But yeah, a true mono cartridge really brings new life to mono records. It was a revelation for me how good it is.

mulveling, that’s what I assumed. No guarantee, let alone "dramatic difference".

@inna Well, it can actually be quite a significant difference, but most of it is usually "personality" rather than a difference of "quality" level. Moving coils each have a distinct sonic fingerprint caused by choices made on magnet, pole pieces, coils, wire, overall design - cantilever and stylus too!

A Van den Hul Colibri sounds worlds apart from a Koetsu. Both have their fans. There is only a small number of MC motor designs; many still use the classic magnet-yoke system which goes back to Ortofon’s SPU of the 1950s. Ortofon has used a very different motor design in high-end models since its Jubilee MC (coils mounted INSIDE the magnet in very compact form - look at MC100 or MC200 too). Clearaudios are using something different again (coils like a dumbbell with pivot in middle). Colibri is "monopole", no front yoke pole piece, which is why the motor sticks out so much (and probably contributes to its sibilance too). With the classic yoke designs, you get a classic warm "vintage" sound with "softer" magnets like alnico. Or you can "harden" it up and push it towards more modern hifi sound with neodymium. Samarium cobals sounds close to neodymium. Platinum magnets sound somewhat between the two extremes, but Koetsu bought them all up. Oh and Lyra uses a variant of the yoke, with non-magnetic pieces but an extra magnet mounted in front! I find this all fascinating.