Changing the bars on my 07 fatboy again and am wondering if there is any advantage to heavy duty or polyurethane bushes.  Theres nothing wrong with whats in there but I have heard the heavy duty or poly ones give a better feel to the bike.  I am fitting a set of 1 1/2 inch 32 inch wide t bars that weigh about 3.5 kgs, not sure if the weight needs to be better supported.  Thought if it was worth doing I would do it all in one go. 

Thanks in advance.  

Just be forewarned that the poly bushes are generally far harder than the rubber ones and have different vibration damping characteristics. You should notice an increase in the vibration - not much and potentially the vibration free sweet spot will change to a new RPM range. Some folks love them and others really hate them -I have tried both several times and prefer the rubber ones for damping.

But by all mean give the poly ones a try as you never know until you do and they are easy to swap out (unless you have the cabling running though them like I used to....never again on that one as the job becomes a real PITA)