The best replacement for vex is ftc.

The best alternatives to vex are rated as following:
★★★★★  ftc
★★★★  mindstorms
★★★★  nxt
★★★★  tetrix
★★★  mindstorm
★★  ev3
★★  vex iq
★★  irritate
★  annoy
★  first robotics
★  fischertechnik
★  tenacious
  lego mindstorms
  delvin
  frc
  fll

Your alternative for vex is not listed? Suggest!
Speaking about vex, one probably shouldn't forget about robotc.

Other search terms related to vex and their ratings are:
★★★★★ robotc
You have in mind a companion for vex and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of vex in all years. Click on graph for more.
vex
ftc
mindstorms