Are there generally accepted signs that your setup is either too stiff or not stiff enough? I've been thinking about this for the last couple weeks, and have been doing some research, but the "facts" aren't obvious to me. Lot of opinions, so maybe it's more of a subjective, rider-by-rider, feel thing.

I have a base tarmac, and sometimes it feels a little soft when I would like a little more responsiveness. I ride for fun and for exercise, so I'm not losing sleep over this, but I wonder if I could go to a stiffer frame or wheelset without any negative effects. I weigh 195 and wonder how much that would play into my perception of stiffness vs. somebody who weighs 150.

Any thoughts on this?