Cartridges

IMO an ulrasonic cleaner makes a vast difference to new and old vinyl alike. If you have a lot of vinyl it is worth having one as it is amzing the difference it can make to the sound.

Agree with the view that the quality of the pressing makes a vast difference - I rely upon discgogs to find user reviews of all the various pressings and it helps you to find better pressings

Cartidge should be well matched to the arm and table (and system in general).

Separate issue from the records. I almost exclusively buy new, and the audiophile ones typically sound great (especially the 45s), although if the original tapes aren't good, the mastering can't correct for it.

Catchy title. OP could have put entire query in title. 

I had a VPI classic 3 and an Ortofon Cadenza black and switched to a Dynavector XV 1S and it a was a nice upgrade.  I still think the Cadenza sounded really good and had a lot of that next level sound you get from the best carts.  I don't know the blue but I would guess it would be really good.  Also Hana Umami Red is really good.  I never tried it on the VPI but it's great on the Rega P8

For starters, you require an excellent cartridge to clearly hear any record. Lowest grade cartridge I would use is a VM540ML. My current HOMC cartridge plays with $1K+ cartridges. I could buy better but am satisfied.