I am new to this thread, so...hello all.

I must concur with those who say that a new wheel set will upgrade your bike.
At almost 67, I have been riding for three years after a 45 year absence.
I ride around 5,000 miles a year on my 2004 Orbea Mitis. (I bought it used.) My average ride is 35 miles with 2,000 - 3,000 feet of climb.
I ride Campy, so I had Campy Vento wheels.
After the need to replace my freehub, which was impossible because Campy changed the specs and the new freehubs would not fit, my local bike shop suggested that they build me the right wheels for my riding.
Campy Record hubs, Mavic Open Pro rims and DT Swiss spokes went into the build.
From the first ride on the new wheels, I was riding faster and with much less pain. I live in the Pennsylvania hills and climbing was where I really noticed the difference. I was able to climb much faster and easier (not that climbing these hills is easy) than with the Ventos.
The wheel set is the best upgrade one can make.