I don't have the energy, and you don't have the patience, to deal with all of the places my mind went in this mental tug-of-war. So I'll skip straight to where I ended up. It seems that making an objective decision about the best approach is pointless. If we are really honest, we'd probably admit that our objectives aren't all that simple or even constant. Instead, they are quite multi-faceted and dynamic. That lands us in the realm of the subjective.
For most of us, it is never all about speed, or all about out-performing your ride buddies, or all about carrying stuff. There is a balance between light weight and durability, aesthetics and function, speed and comfort, etc. The truth is we want more than one thing, and the way we each evaluate optimal is different. That's okay. It's your money, and I don't need to tell you what optimal should be for you, or how to achieve it.
My evaluation of optimal varies within the same day. This morning, I had a hankering to ride fixed. Even though I fought a headwind for an hour, and my one fixed gear was not optimal from a speed perspective, I wanted that sense of momentum and being a part of the machine. At the moment, it's the only fixed gear bike I have, so in that sense it was an easy choice. I didn't finish the ride as quickly as I could have on a different bike. I was out there enjoying the machine connection a little longer, and that was fine with me. In fact, it was preferred. Of all my bicycles, the Kogswell P/R was optimal. At least it was until this afternoon.