Neither - it is not a competition to see how long it is about how good the quality, the creativity, the situation, the mood the time place. The more thrilling the situation the more turned on to the man then it can be a quickie, or a long sensual fuck in an unusual place or circumstance. As to size yes big can be fun but it is the same as stamina it is about the man, the mood, the timing, the place, the situation and how exciting it is perhaps a little ricky like in public with a man so turned on he cant wait ... the more passionate and turned on the man is the more exciting the sex is.
Both size and stamina. Size means not too long and too fat dick it must me 6 to 7 inches long and must be 2.25 to 2.5 inches thick. Mot less than it or not more than it. Shorter and bigger than it both are not pleasurable for fuck for me. Stamina i like more and more mist time fuck givez me most pleasure