One turntable with two arms, or two turntables with one each - which would you prefer?

In Use, things evolve: 

I have a lot of Jazz LP's, many Mono LP's. There is nothing as easy as having a Mono cartridge ready (mounted, aligned, azimuth/overhang/vta/tracking/anti-skate) all set to go, play some Oscar Peterson Stereo, up comes a mono LP, switch arms, select arm C on the SUT, change the Mode on the preamp to Mono (or just a single speaker), then back to arm A or B for Stereo.

Original Idea: I had 2 arms, mono in the back. I was selling LP's, giving them a farewell listen. I realized I was wearing out my MC Stylus when I could have been using a MM with a replaceable stylus. That's when I added the 3rd arm, left side backwards for Mono, rear for MM or MC (mine and friends cartridges we listen to); right long arm favorite MC, fixed.

Thanks everyone. It's cool to read everyone's take on the question.

I don't know how to answer the question for myself - yet, at least. The reason I'd be interested in having a second setup is that I love the idea of having setups optimized for different sonic signatures, but don't really want to deal with resetting vta, vtf, etc. every time I change cartridges.

As I've thought about it off and on throughout the day, and read others' responses, I've honed in on a couple questions I need to answer for myself: do I really need a mono cart (same situation here @dogberry) and/or do I want both a suspended and non-suspended table for variety? I've only ever lived with non-suspended tables and am curious about suspended tables, lately.

In any case, I fully agree on the importance of a good phono stage. I'd be inclined to go with a single phono stage with multiple inputs, and get variety from table/tonearm/cartridge combos.

@noromance, I checked out your system. Great solution for vinyl storage! I'm getting too old to crawl around on the floor trying to read spines.

Obviously 1 tt with 2 arms and an adjustable phone stage. There is no question about this. The Kuzma Stabi R is mentioned above.

I prefer having 2 turntables and two arms over one TT 2 arms.

Why, because when I had multiple arms on one turntable I wiped out my Koetsu reaching over the back of the TT to lower the arm.

On the second TT I have a tonearm with headshell so it is easy to swap cartridges.

My main TT is my reference which I like to keep with best arm & cartridge.

@lewm … “I think that makes me —- crazy”. 👍👍👍👍. I mean, it’s OK… most folks think the amount of money I put into my system is crazy… although… three or more hours of listening a day… and the enjoyment I get, seems well worth it. 
 

If having many TT and cartridges makes you happy.