its all personal preference at the point in the market these markers are at, i suggest you head to the field and ask someone that has either if you can try it out. its the only way to figure out what YOU like and dislike about each.
but seems how you asked I'm totally in favour of the gt... or if you cant afford that get the vx (i shoot a vx), but i have never really been a fan of the luxe from day one... dont know why just never liked them.
good luck