Plan to get the RMC wah, now just comparing the 4 and 8, since there is no local dealer in my city, hope someone who can give me some opinion. I love vintage sound, and I play everything beside metal. I watch lots of videos of RMC 4 and really dig its sound, even there are not much RMC 8 videos, but it still sounds fantastic to me, and also I am a big fan of John Mayer. so which one should I choose? what is the main difference between them? Thanks!