I'm a user of kenwood 5039 too! lol. I believe 4050 pioneer has 3 RCA Outputs while 5039 has only two. Well, depends on how you wanna place your setup..it makes a big difference. For me, 2 RCAs are enough. In terms of sound, i don't think there's much a difference between 4050 and 3050..but if you could go up to 6050..it would be a big difference in sound production