Ian,
Your point about choked condensers is certainly valid and every Esprit will suffer with that problem at some point if the rad pack isn't dropped and cleaned regularly (royal PITA as you know) due to the ground level intake position, small opening size and very close spacing of the radiator fins which doesn't allow much debris to flow through.
I think the difference in our opinions of the performance is relative to the climates we are used to. I've owned 5 Esprits and even when working properly, here in Florida where 95-100 degree temps are the norm during a good part of the year, none of them performed any better than what the local guys here would consider below average for a typical vehicle. The angle and large glass area of the windscreen generate so much radiant heat that you have to have a system designed with "overkill" in this car for these conditions, particularly after it's been sitting in a car park in the mid day sun and the cabin temps are 120 degrees.
I guess it's all relative...