While I suggest a 5 wt as the first rod of choice for my area for someone that wants one rod, I hardly ever fish mine these days. I either fish something lighter or heavier depending on species and conditions. If you already own a 5 wt, I also wouldn't suggest the 6 wt, it is still too close to the 5 wt. Either a stiff 3 wt or a 7 wt would round out your collection better if you like your 5 wt. Personally I either fish a 4 wt these days or a 7 or 8 wt.