Cartridges

You’ll probably get more out of the high end vinyl, with a better cartridge.

hysteve

I upgraded my cartridge from a Kiseki Purpleheart NS to a Grado Aeon and am delighted by the improvement in sound froma wide range of records. A much more detailed, richer sound with a wonderful ambience - feeling of space as elements are much more clearly seperated.

Just be careful to avoid having any transformers near the cartridge as it will hum!

I haven't had the pleasure of hearing an Epoch3 or Aeon3, but the Statement3 has taught me a lesson. With an output of 1mV it can be used as an MM or as an MC as far as the phono stage is concerned. I found it decidedly boring connected as an MM both with a Quad 24p and with the NuVista Vinyl. But as an MC with the resistive loading set low at 100Ω it comes to life and is really giving my London Reference a challenge.

It looks like you already have a solid base for vinyl reproduction, so yes, you're probably at a point where better vinyl would be a wise way to spend your money.  More music!

Before spending on a new cartridge, I'd look at your phono stage as the next upgrade.  

I’d say both, but if I had to pick one, it would’ve the good recordings/pressings.