I also own a Technics sp10 mk3 I never mentioned it as while it is a lovely object to own I don't really consider it a worthy option. The reason is that I always find mine quite mechanical and grey sounding I have spent a great deal of time isolating it from the outside world but still never does it for me or course this is only my personal observation. Again I have very close friends who adore the technics and simply love it and so they should it all comes down to so many factors apart from sound.
I have a friend who owns a Rockport direct drive this is an interesting beast for sure for me more like the ultimate contender. Recently I noticed on audiogon there was a lovely Goldmund reference for for this is also a great vintage turntable superbly executed and lots of fun indeed.
As peter mentions the the arm cartridge factor is quite a serious consideration with all these wonderful turntables thats why I always end up owning a few turntables at one time. I personally favour air bearing tonearms in every way again you will get many who say the bass is weak and maybe in some ways it is, but with careful cartridge matching for me this can be addressed. I just find the sound of air bearing arms just less mechanical and ultimately more involving. The wonderful thing is that its not my opinion that matters and there is so much choice these days this is what makes it fun. If I had the space or the funds I would own 30 turntables yes it would drive me crazy but think of all the fun I would have not ever really knowing which one is is the real ultimate.
Now that is a great post for me one of your key words was (involving) if you do not have that one point in spades long term goes right out the window. A few points that seem to get lost are is the company able and willing to stand behind their product long term 10 to 20 years. How hard is the set up and does it stay set up or is it a problem child. For long term simpler seems better to me IMO only . The more belts, hoses, Heated bearings, the more bearings, Air pumps, fluids, Servo motors , and voodoo you have the more to go wrong.
Who ever said ( the best analog front end is the best set up analog front end) said a mouth full and the simpler it is the better chance it might happen. Gadgets are cool but do you need them long term.
Things I have added and used long term a good record brush, a good light over the table , good record sleeves, cleaner fluids for the needle , a demag and ultrasonic record washer. Some cheap some not. Things I added and did not use a analog to digital converter and a computer inventory program for records. Some of it is personal are you the type to come home and mix the perfect cocktail with all fresh what ever or are you just going to open a beer. Simple is not worst thing you can do and better is not always a add on or expensive .