Alternate Cartridge: Preferred/Better are separate considerations.
Sound Characteristics (do your research) are preferred, not better.
Imaging, is better, not preferred (good, better, best) and is vitally important. Imaging is improved by wider separation and tighter channel balance. The difference is easily recognizable.
Regardless of Phono EQ, Preamp, Amp: start with better imaging out of the cartridge. Change your Phono Stage, it will be the same: (preferred, not better) In any case, it receives better wider/tighter signal
your 20x2 produces 25db of stereo separation (mediocre), and 1db channel balance (good but 0.5db better)
Cantilever: 20x2 is solid aluminum rod. I never heard that. Stiffer material is better, in my experience: especially tighter bass. Boron, and Crystals are Stiffer than aluminum. I get Boron, not just a bit less money than crystals, but less likely to shatter a boron cantilever than crystals. IF you can afford them, and be very careful with it, then go for a crystal cantilever. I have a Sumiko Talisman S with Sapphire Cantilever, more/tighter bass?
We can convince ourselves of anything, but it seems so. I use two wonderful LP’s, ’Cecil McBee – Alternate Spaces’, (India Navigation – IN-1043) and ’The Bass’ (3lp set) (Impulse ASY-9284-3), an amazing collection of music/musicians/engineering.
All advanced stylus that are close to the shape of the cutter sound great to me. I have heard MicroLinear; MicroRidge; MicroLine; Line Contact; SAS; Shibata; Van den Hull; Geyer II. You can never do a direct comparison, each was on a different cartridge, so I would not let which advanced shape be the determinant.
All advanced stylus shapes MUST be properly aligned.
MC Moving Coil: Low or High Output. Low Output allows smaller/lighter coil, thus theoretically Low allows the advantages of MC, more refined signal. I have only heard Low Output thru my Step Up Transformer.
MI, Moving Iron: I have never heard one, highly respected by many.