To those with multiple tables/arms/cartridges

3 tables, 4 arms, 5-6 cartridges. Now that I have 2 arms with detachable headshells, I hope I will get to hear all the cartridges in a more regular rotation. One arm has mono cartridge. The rest are all stereo MCs. I think while some set up is better than other at certain type of musics, in general they can play wide variety of music well so just a different flavor depending on my mood. Thinking about adding an MM or MI just to have something different and wider palette to choose from. 2 phono with 3 inputs available so next project is to add more phono inputs, I think.

Multiple tables, arms, cartridges, is like when you go to live classical performance, should it be at Musikverien, Carnegie hall, Boston Symphony hall? Which orchestra, Berlin, Vienna, NY, Chicago etc etc, which conductor?
You could try to search for one absolutely best combination for all things. However, my feeling is that one absolutely best combination is unlikely to be absolutely best at everything. Each hall, each orchestra, each conductor has their own acoustic, their own characteristic. One may be better at certain thing in absolute term but it does mean that other does not have anything good or interesting to contribute. It is not as fruitful to have multiple digital sources but I think top notch analogue front end can offer equally valid but rather different presentation so why not have a few!

I don't know what an audiophile is supposed to be. In an ideal world where all recordings are made equal and there are no evil or incompetent recording label/studio/engineer, all recordings are made with absolute transparency and fidelity, honest to the musician's sound, then I could see myself with single source, single system that is totally transparent and have absolutely no sonic signature of its own and let the recordings do all the speaking and singing!
Unfortunately I am not in that world. There are some recordings that will sound great in absolutely transparent system. On the other hand, there are some great music on recordings that will just rear its ugly head when you expose it ruthlessly. I don't know of any cartridge/arm/table combination that can ruthlesly reveal all the glory of well made record but at the same time, forgiving the less than perfect recording that are great music wise. Some recording can benefit from a little bit more warmth, has piercing treble that can benefit from a bit more roll off top. Some are so good that you don't want any coloration from the equipment to interfere.
I suppose, if I only care about the sound, I can just toss the bad recordings away and end up listening to a few selected sonic spectacular recording through my single source system. However, I want to listen to great music and sometimes, some of those recordings may benefit from slightly different coloration/presentation by different setup.

Dear Raul, I supposed one day when I find a combination of cartridge/tonearm/table that is superior to everything else that listening to other combination does not derive any pleasure anymore, I will be down to one setup only as well.
At this moment, I would say Lyra Atlas is overall the best cartridge I have so far but not much better than Air Tight or Koetsu in every way and I still enjoy listening to those 2 cartridges very much as well. Could I live with just the Lyra, sure but why should I deprive myself of Air Tight or Koetsu when logistically it is still easy to keep both of them around. I made a compromised when I bought my piano. I only have one, a Grotrian. If I have a big house and a lot more money, I would not mind having a Steingraeber, Fazioli or Bosendorfer as well since they all sound different, very different feel and touch when you play them but since I only have room for one, Grotrian it is. I would not mind having a Maggie 20.7 or Martin Logan CLX just for variety but logistically I cannot have them so I settle for one pair of speakers only.

Luckily I have enough room for a few turntables, arms and cartridges so until I find the ONE, I'll settle for the few that I have :)

Halcro, I see, so we both have TW, FR66s in common and now Grotrian as well! I have a Grotrian 192 in standard gloss piano black. Grotrian make some of the best upright pianos that I have ever tried and when I came across an excellent offer for 192, I just could not pass it up.

Halcro, unfortunately my car is an 11 years old Honda CRV and my major transportation mode is walking as it only take me 15 minutes by foot to get to work but in Bangkok traffic, it may take me up to 30-45 minutes by car to go the same distance. I use on average about 1 tank of gas a month in my car so a good car is a big waste on me :(
I think the cost of my TW and Reed 3Q/FR-66s, Air Tight and Lyra costs quite a bit more than current market value of my car by quite a bit! Not sure if that is a good or bad thing.

I never had a chance to hear vintage Grotrian but had a chance to play on a few vintage Erard and Pleyel that were kept in excellent condition. I am sure it must be wonderful.
I would say current Grotrian upright is still one of the best up there with current production piano. A few years ago, I was in Geneva and visited few piano stores that had a few Grotrian uprights, Bluthner, Sauter and C. Bechstein among others and I had a lot of fun trying them all out and thanks to the piano stores that were generous enough to let me try them even though they knew that I was not looking to buy a new piano at that time.

Back to original topic, I think I need at the very least 2 arms and 2 cartridges though, one stereo and one mono!