I'm going to start making my live rig straight-into-PA, and use my 5150 for when there isn't a PA. I know I want a POD HD, but should I get the HD500 or the Pro? It seems like there really isn't a difference between the two. I feel like having the Pro would be better, but it would also need a rack and the L6 shortboard controller. It's also more expensive. What are your opinions?