IMHO (and my opinion isn't really worth much, as all my bikes are some flavour of 'heavy') you have to consider the whole system. That means the weight of the bike as a fraction of the weight of the bike plus rider plus luggage. In my experience, a few kilos here or there are easily lost in the noise unless you're literally doing nothing but climbing all day. Other factors such as ergonomics, aerodynamics, weather conditions and rider physiology and psychology make far more of a difference.
With a touring load, I'm measurably faster on the HPV Panzerfiets[1] than I am on my (slightly lighter) Dawes, mainly I think because of the much greater comfort meaning fewer short breaks - four panniers destroy most of the aerodynamic advantage of the recumbent. Without a load, I'm still faster on the Panzerfiets as the improved aerodynamics make more of a difference than the increase in weight, an effect that obviously increases with flatness of terrain and headwind. In reality, the wind direction and whether my digestive system is cooperating that day make far more of a difference.
You never get back on the descent what you lose on the climb, but on rolling terrain high-speed recumbent descending enables you to carry enough momentum into the next climb that you can roller-coaster a lot of the way up, to the point where it's entirely possible to keep up with (and on a good day, smugly shoot past) lightweight uprights.
[1] Shouldn't it be Panzerrad?