I will chime in here since I am a Big LRD fan. LRD is a local shop for me and I love those guys, especially their engine builder. Great customer service too. I've run the LRD pro 4R and found it was an awesome system. It is a hair loud here for Oregon since we have strictly regulated DBs, other than that I thought it was great overall. Good power gains, great craftsmanship and hands down customer service, especially if you talk to Jamie.
$400 seems a little high for a pro 4, especially off of ebay. I can get you a Pro 4R full system for about the same price from them if you are interested? stainless full system with ballistic coated silencer. Shoot me a PM if you are at all interested.
Great investment in my opinion