The only reason I can see for ugrading, is if the new bow offers you something you don' t already have. Then you have to decide if it' s significant enough to justify the cost. So, the question is, just what does this new bow offer you? Like you say, there isn' t much increase in speed and I' m quite sure they are similar in the area of accuracy. Neither is loud and there is not much difference in ATA length.
I can think of a few reasons I might upgrade, but only to a bow that offered something quite different from what I already had. One would be if I was looking for a much higher brace height, or a lot more speed, or maybe even a much longer or shorter bow. If you keep a bow for 8-10 years, technological advances will probably justify an upgrade to almost any bow. Sometimes an upgrade is justified by something as simple as money that' s burning a hole in my pocket.
