Subjective or Objective - Which evaluations can be trusted?

If we care; and many don't of course, how do we evaluate any product or system. In my case I have been seeking a fast bike so that I can ride with local DF riders and keep up!

Here are some typical statements found on bent Forums.

My bent is really fast :Subjective
I averaged 35 kph for an hour this morning :Objective
The P-38 climbs really well :Subjective
With a tailbox fitted, my bent is faster :Subjective
With a tailbox my bent reached a higher measured speed than without :Objective

You can generally trust objective statements - those that include measurements - more than subjective statements. As in all things it's not totally clear cut, because measurements may not be reliable and there's always a limit to accuracy. Likewise, subjective statements can be surprisingly accurate if they come from enough people.

I chose my P-38 based on the subjective assessments of past and present P-38 owners and of Bentrider forum members.

I confirmed the efficiency by direct measured comparisons with the other bikes I've owned.