Does anyone run 2 or more turntables...

Yes. Different tonearms and carts. Second one is set up and used for mono.

Drumarty,
I see that you've been a member since 2008. Haven't you noticed in that time that a number of members have 2 ,3 and sometimes more turntables? I'm sure that the reason is because they can afford it, and they want to exploit the strengths of one or the other for different types of music.
I'm sure they will tell you in this thread

Yes, if you have mono lps, you need a cartridge that is design for them. So, two tables.

For the same reason I have three systems: because it's fun.

I have way more than 2 completely set up tables. Never know when you are looking for a different sound.

Each combination of table/arm/cart is going to give you a unique sound of it's own.

Plus...I'm just crazy when it comes to analog playback.