Satsun643,
Purchasing a used cartridge is riskier than buying other used components - they're fragile and consumable. If the savings is significant and you decide the seller is trustworthy then it might be worth a go. I'd suggest speaking to the seller in person. Your feeling for their vibe might be a better guide than some feedback number.
The one time I tried I may have been (slightly) burnt. I think the cart had more hours on it than the 50 claimed by the seller, but it wasn't extreme and there was certainly no way to prove it. OTOH I got a $1500 cartridge for $750, so...
I've A/B'd Airy 2, Airy 3 and UNIverse against Koetsu Urushi (not Vermillion) and RSP. All three ZYX's were more neutral than the Koetsu's, which were warm and had rolled off transients (too which I'm particularly sensitive and which I find annoying). Stone body Koetsu's come closer to neutrality but they're much more expensive.
I've heard the XV-1S (not XV-1) and it is also a neutral cartridge. It has more bass slam and heft than an Airy 2 but less finesse. It didn't go as quiet between the notes or portray inner voices and fine harmonic textures as well. A great rock or big band cartridge, not quite as good for classical, small group jazz, folk, etc. - at least to my ears. The Airy 3 is nearly as energetic and does those finesse things a bit better. Take your pick!
As Larryi said, much depends on the individual system. Even more depends on your sonic preferences. At this level there are few truly bad choices, but many differently interesting ones.
As my friend Nick says - enjoy music, tolerate equipment,
Doug