You're right about 'true-bypass', it's just sending the unaffected signal on down to the next box without entering the circuitry of the pedal you're bypassing. If you're using a wah in you effects chain, I don't think it matters where it is, it's still there and I don't think the difference in tone is great. The best test is your own ear, try the wah up front, then at the end of the chain and see if you notice any difference. Personally, I put my wah on the right because I use my right foot to 'wah'.