I'd say get a Nikon while you can but since you say warranty is important to you and they are getting out of riflescopes, maybe not. They'll still be around to honour warranties but that might mean partial refunds or credit notes toward other Nikon stuff rather than repair/replace a scope. If you don't like Bushnell or Vortex you go with Leupold and face the same problem: Fulfilling warranty commitments costs money, it's paid for in the purchase price. If the warranty isn't limited to the original new purchaser, that unlimited commitment will show up in the second hand price, too. But as long as a Leupold was imported by Korth, they'll back it, so if you like their scopes you can decide it's worth the extra.
I like the modern Weavers made in Japan, the Classic K and V models, but warranty was always going be complicated by having to return them to the company in the U.S. so I've only bought two new (an R4 and a K4 Scout.) I have an R4, a V3, two V9, at least three K4, two K6 all bought used, never any fault or defect with any of them so far.
I also like a couple of Bausch&Lomb Elite models that I acquired second hand, a 3000 series 1.5-6x and 4000 series 4-12x40AO. They have been good value
and Bushnell honours the warranty on these.
