IMO it could depend on individual eyesight. I've got a newer VX1 3-9x40 and two VX3s in 3.5-10x40 all bought since 2012. I've also got an 1989 Vari-X III 3.5-10x40 I bought used a few years ago.
I can't see enough difference in the optical quality in the VX3s over the old Vari-X III or Vx1 to justify the considerable price difference of a VX3 over a VX1 or VX2. I'm not saying the difference isn't there but I can't see it. YMMV.
There isn't, if you always shoot in sunshine and like heavier scopes with friction adjustments.