Day after day I ride the trusty Cross Check to work and play. It's a great bike. I could get along with it and nothing more. But I used to race and train. I have a sportier bike. I've even dialed in the components to suit my current riding style.
I used to commute on the road bike. I stuffed everything into a bum bag. I had a selection of different sizes to hold the changing loads as a typical season developed. When I started to dislike the increased saddle pressure of a body load I built a dedicated touring commuter with a rack.
The Cross Check has gained weight as I've added useful features. My average speed slips a little lower, but the goal of the bike is not absolute top speed.
Missing the speed and handling of the road bike on pretty summer days when I'm feeling frisky, I kept considering my options to add a rack. I didn't want to use P clamps. I could use a rack that mounts to the brake center bolt and attach the lower end of the legs with some old Blackburn custom eyelets. You can also fake those with faucet washers. But I'm reluctant to turn every bike into slightly different versions of the same thing.
Then I spotted a nice frame pack by Banjo Brothers in the QBP catalog. I love bags and packs. So I got one.
The road bike launched me to an average speed two miles per hour faster with no additional effort. It's the bike, not the rider. The frame pack needs a few tweaks, but the basic concept is very satisfactory.