Is it worth upgrading my current turntable setup?

See if you can audition a Rega 3. It will sound different to the Pioneer and you might or might not prefer it. But it is a good yardstick in terms of assessing whether you want to explore belt drive turntables.

@blue_collar_audio_guy , nice system. If you want to make your system sing at it's best you have two issues to fix. The first is subwoofers and a two way crossover. Those little woofers are responsible for a large part of the audio spectrum. The upper frequencies it carries is being distorted by the long excursions low bass requires. If you take the low bass away distortion will drop noticeably and you will get an additional 10 dB of head room. The result will be a system that is less harsh, more effortless and with superior imaging. You will have to buy at least two subwoofers and a crossover. What is included in most commercial subs is a pitiful low pass filter. It will not roll the bass off to the main speakers losing 1/2 of the benefit of getting subs.  

Next would be the turntable. Here is the problem. In order to get a turntable system that will be noticeably better You are going to have to spend $10,000+. Intermediate steps are just a waste of money. A good turntable will last you a lifetime. Do it right and do it once. Stick with Kuzma, SME, Sota, Basis and Avid for turntables, Schroder, Reed, SME and Tri Planar for tonearms and Ortofon, Lyra and My Sonic for cartridges. Stay far away from 12" arms. They are inferior to 9" arms. Proper record clamping is a must either reflex or vacuum. 

If you want to learn a lot about turntables watch this video. It's only serious mistake concerns anti skating which in the view of most of us here is totally and completely mandatory. 

Woops, add Kuzma to the tonearm list!

The PLX-1000 is a really solid performer and you have a great cartridge. If you're not completely happy, try to zero in on where the sound signature of the TT is lacking, and look toward specifically addressing that without throwing the baby out with the bathwater.

The good news is you probably won't have too much trouble selling the PLX-1000. But I'd keep the 2M Black. Very tasty.

Have fun!

Spending money on analogue is nostalgia, streaming nowadays beats it by a country mile.