When properly set-up and taken care of at least sound-wise I don't think new TT are that much superior. Of-course you need to have a good starting point, but I remember when I got things going with TD166 It didn't shy from Rega P3 at all.
When this and if that. Like I said, with proper maintenance a top table from the 60-ies or 70-ies can sound good. But it's always the arms. I have several Lenco idler drives that sound great but the arm is problematic even with new v-blocks. Not to mention the crappy headshell that is horrible to mount a normal cartridge on. And the wires... Ugh. But when refurbished properly they are pretty good.
I also have a TD115 that took me months to get right. And then it sounds 'meh'. I have a TD150 that I took in to fix 30 years ago...it's still not finished. The arm was crap. I'll just be using the platter and spindle if I ever get it finished. I have a Rega RB301 arm for that that I tried also on my current table, and honestly, it's solid but it doesn't sound very well with my MC cartridges (not because they are MC but I can't get much more out of it than my MM cartridges can offer). I had high hopes for the rb301 but it is disappointing to me.
I have several top model Dual TT's. The 1219 is in working order and plays ok. But again...the arm! The headshell works ok and I can quickly swap cartridges. But it's never a solid connection. Prone to oxidisation of the sled contacts. The arm is to light, not stiff enough. An other Dual has a problem with a broken RPM knob. I tried to fix that but oh man! It is so complex! I can't get the parts for a decent price. The cables are old and bad, no RCA's. All that stuff rattling around in the plinth. And look at the 'quality' of that plinth.
I have a couple of Garrard idlers. Not the 301. Cheaper models. Unusable. Plain old crap. Wasted money. Even if i only payed €25.
I have an Akai tangential which is actually a Technics SL5. I put in a new T4P cartridge that is just ok (Tonar HE) and the result is meh. Ergonomics 10, sound 5. Good luck trying to find a better T4P cartridge. No direct drive for me. The Akai though, that's nostalgic catnip for me from when I couldn't afford it.
And which old turntables do I like then? Apart from Lenco with a new arm. The ones I never expected much from. I hate Philips. Because my dad bought one that I played with until I could afford my own. Sold on the reputation of older models while this one was automatic and built to a budget (even if it was the top model).
It's always the ones you don't see coming. First this ugly 80-ies tangential FP146 I bought for €10. Refurbished and fixed everything. New cartridge (there hoes another €10). And a thick platter for extra mass. Unbelievable how good it sounds now.
And now the iconic Philips 212 electronic. Once I scraped off the liquified belt (aging, common problem) and put on a new one it just worked. I renewed the old cap (also known problem) and cleaned it up. It's a suspended TT which makes it rather wobbly. The arm looks thin but works fine. The headshell sleds are a point of contention. But it works and sounds great. And the electronic tip buttons are a joy to work with. The speed stability is the best I measured for any turntable.
So that's a load of hard work and nostalgia for you. But as for sound quality nothing beats my new turntable. It just beats the crap out of my digital system, which is also no slouch. It's not a coincidence that it does as I've been upgrading for 40 years. And I know what I like and what works.
BTW: This is all my own stuff. (I could start a museum by now).
This is just a pic of my current table. I said this was a picture thread.