The days of the metal ferrule that added significant weight to the rod and noticeably impacted the performance of the rod are long gone. The modern integrated ferrules add very little extra weight to the blank. As an example compare the 2pc. models
here with their one piece counterparts. Granted a couple of the 2pc. models differ in action or lure rating a bit, but most are designed to be quite close to the one piece rods.
I highly doubt that many would be able to discern between rods with various numbers of pieces if handling them blindfolded. The ferrule just doesn't impact the rod the way that it once did.
With that said, I prefer one piece rods when I can get away with them, not because of the sensitivity issue, but because I don't like to spend time during a fishing trip assembling rods, and checking ferrules. Each ferrule also creates higher stress points at either end, though a good blank design takes care of most issues related to that stress, an improperly seated ferrule can cause problems and possibly result in a blank failure.
When I can't or don't want to transport long rods, I have 3pc. and 4pc. travel rods that serve their purposes very well. They are great because I can tuck their tubes behind the seat in the truck, and not have to worry about them being damaged in transport. They just don't spend much time in the boat. If I decide to make a quick trip on foot, they are there, ready, and reliable.
Joe