hi dave
I have full width renthals with oberon weights on. I think cos of the width of the bars it makes up for less actual bar end weight. Generally I dont get vibe problems, though I also agree with mike to check carb balance as IMO a full monty engine does vibe a tad more than stock particularly around 4 k rpm. Hence any out of synch is more noticeable.My speed triple by comparison is ultra smooth, the engine having better balance...maybe the FI helps here as it dont go " out of synch"..vibration is an odd topic since some vibes affect riders more than others.
Generally I find the fazer to be a bit rough at low to med revs even after carb synch, but never enuff to give me numb fingers.