Young or old, if you go into the full speed shafting action, you'll last relatively short. It'll be intense for both guys, and if this is what they want to experience or if this is what their preferred scenario is, both dudes have a relatively easy job ahead of them.
Quite a few guys actually like this kind of play. The top wants to get his rocks off. The bottom can take some serious pounding, and enjoys it but cannot last too long without feeling discomfort. In other words, some dudes are great sprinters and the others make awesome marathon runners. There is really nothing wrong with either kind.
Enters the heteronormative world, and the tops are being told that it is their duty to last as long as possible, and the bottoms are being told that they have got to keep their legs in the air for hours at a time. If you subscribe to this scenario, possibly because you believe that you may enjoy it, you need to develop some technique to extend the pleasure (if you find it pleasurable) for as long as possible.
So, the top dudes take their time and start prepping their bottoms with loads of rimming action, dildos, etc., until the bottom dude gives in, and begs to be fucked already.
Younger dudes have a typically short recovery phase, and can afford to shoot their first or even second load in a row relatively fast, because they know that the the third one will take a relatively long time to accomplish. Older dudes, resort to interruptions, edging, and slower pounding action because their recovery phase is long, and relatively few mature men really enjoy shooting for the third time in row.
The rest of the gay guys fit in-between the sprinter and the marathon man paradigms, and are more or less tuning it according to their needs, and the actual circumstances of the encounter.
Try one. Try the other. Try being in the mid-range, too, and choose what works best for you.