Cartridge upgrade for vintage TT - MM or MC?


I have a Technics SL-D202 that currently has a Sumiko Pearl on it, which is OK but I don't totally love it. The midrange is nice but the treble in particular is lacking. Compared to my digital source it sounds dull and lifeless and therefore I hardly use it.

My question is, would it be at all worth it to upgrade the cartridge or should I just wait until I can upgrade the TT totally?  I am considering the Schiit Sol in the future if they ever get it back on the market but my wife really likes the automatic function of our current table so I may be stuck with it or something similar at least for now.

I had considered trying a lower-end MC cartridge and seeing how that sounds but any other recommendations would be appreciated.

I use a Schiit Mani pre which can be adjusted for any cart (or so I'm told).  

The table came stock with a AT-71E and I also tried a Shure MX97e but neither of those really wow'ed me.
elangley01
It depends on the turntable design, many vintage turntables are crap too, some of them are amazing in comparison to the more expensive turntables made today. I am using only vintage turntables, i hate belt drive turntables (no matter new or old). But i like all my vintage direct drive machines.

You can always buy new Technics SL1200G or GR to save your time, but if you're really into vintage analog gear then nothing wrong with it! 

So here's something interesting. In my search for new TTs in the same price range I came across some good reviews of the Fluance reference series.

The RT82 ships with the Otofon OM 10 and lists the following specs:
Tonearm effective weight: 28.2g
Headshell weight: 10g
Cartridge weight: 5g
Cartridge compliance: 20

Just for giggles I put these into a resonant frequency calculator and got 5.4 (!)

That can't be right, can it? Am I missing something?
I’m not familiar with the pearl cartridge but if it sounds dull, try to raise the vertical tracking angle a little (no more than 1/16 of an inch) to see if it adds any sparkle. Generally if a cartridge sounds dull & muddy, the VTA is set to low. Again, I’m not familiar with the pearl, so it could be the cartridge. Just a suggestion.
Forget MM cartridges! None of them sounds as good as even the venerable Denon 103 (and its variants)! These have always been my go-to choice for a budget price! When I wanted to add a NEW TT to my collection of vintage TTs I bought a Pioneer PLX1000 direct-drive, Denon 103R and a vintage Denon step-up transformer (SUT). Cost ($700 + $300 +$200) = $1200 for a rig that easily competes with far more costly gear! 
The Pioneer PLX1000 is the hands-down winner in the sub - $1K TT category! Ditto for the Denon 103 mc in below - $500 cartridges!