Honest question about cartridge vs. turntable performance.


I’ve been a vinyl lover for a few years now and I have an ortofon black cartridge setup with an mmf 5.1 turntable with acrylic platter and speed controller. My question to all the vinyl audiophiles out there is this. How much difference does a turntable really make compared to the cartridge? Will I hear a significant difference if I upgraded my turntable and kept the same cartridge? Isn’t the cartridge 90%+ of the sound from a vinyl setup? Thank you guys in advance for an honest discussion on this topic. 
tubelvr1
 The torque of a direct drive motor is now superfluous. A quiet environment is far more critical. You have to isolate the platter, tonearm and cartridge from everything. IMHO this is far more difficult than cutting a lacquer.
Since I've had to set up a mastering operation from scratch I cannot disagree with this more. A lathe has to be isolated too. My setup is pretty old- a Scully- and yet it has a table equipped with adjustable points for feet, plus an isolation base, both made at the same time as the lathe, which was the early 1950s (so if anyone tries to tell you that points beneath your equipment is snake oil, you now have proof that the industry thinks it is not). All the stuff you have to do standing on your head to make it work and not freak out if you look at it cross-eyed is ridiculous. Cutting pressure, track ball height, stylus temperature, tangential-ness, bearing noise (the bearings need frequent greasing and should be warmed up for 20 minutes before making a cut), controlling cutter resonance... I can go on; not to belittle your comment but really its pretty amazing that the technology (record and playback) is as good as it is!

Atmasphere, in some cases it might be because they work better:)
We've made a belt-drive machine for over 20 years. I'd put it up beside any belt-drive made and no worries expecting it to keep up; you can walk up to this machine and thwock the platter while its playing and not hear anything significant through the speakers; the platter is damped, the plinth is rigid and dead, it has a powerful drive and the motor itself is a significant flywheel. Its very neutral. But I think Technics makes a better turntable (and for less money, but I'm not a fan of their arm) so we're not making our 'table anymore...unless someone begs us :)
Linn has just updated the most important part of their turntable, and it is not the motor, the type of drive, the speed control, the tonearm or the suspension system. It is the bearing!!! Precision engineering in the bearing is actually where I believe the biggest gains are to be had, others may disagree, but listening to what the bearing can bring is crucial. Direct drive tables are fine, so long as the motor doesn't cog ( which unfortunately a lot of them do) or contribute any noise into the platter. 
@daveyf, what exactly is the difference between the old and brand new Linn bearing?  
@testpilot There have been two prior bearings for the Linn. The original and then the Cirkus. The new one called the Karousel attaches to the subchassis with a three point system. It is also more precisely machined to a mirror finish at the base. The added rigidity and the precision go a long way in improving the signal to noise ratio. If one looks at the typical bearing that most turntables utilize then one can see the obvious differences. This aspect is not something that we see discussed that much, most naysayers of the Linn platform have no idea as to what the bearing in their favorite turntable consists of, or even how accurately machined it is ( never mind the current condition of said bearing!)...yet IME this is a huge factor in the ultimate SQ.
Mijostyn, I have long ago moved on from the Nottingham, after having also moved on from the Sapphire. Each of my five turntables in current use is either direct drive or (one) idler drive, a very highly modified Lenco, which really only uses the platter, the motor, and the idler wheel from a Lenco L 78. With all due respect to Sota  turntables, for you to talk about a Dohmann turntable with a built-in minus K platform or to talk about any spring suspension in the same breath with a minus K platform is a bit off the deep end, don’t you think.? The minus K is light years more advanced than any common spring suspension found on a turntable. And the Dohmann is indeed a world-class turntable if you have $40,000. I don’t categorically choose direct drive over belt drive, I only claim that for the same amount of cash investment, you get much more bang for the buck out of a direct drive turntable. And even if you have and are willing to spend the bucks, the dohmann and only a very few others actually give you value for money. Most of the rest of them are just bling exhibits. Your ad hoc arguments against direct drive just don’t hold water.