Alrighty, I just put a deck and amp (3.5lbs the amp weighs) and 5-1/4" Clifford co-ax speakers in my 2009 FLHTP. Prior to that, the fairing was empty.

I have noticed the weight when you go around corners....

I can say that I had not ridden the Harley for over maybe almost 2 weeks...and in the meantime, I rode my Ninja ZX14 (that I have not rode in a year!)...although not the lightest sportbike, this could be part of my 'feeling' that the Harley is real heavy?!

I guess I will have to take my uncles FLHTPI for a ride, it has stereo, but no amp....

Could that 3.5lbs make that much difference?