When I'm buying a rod, if I like it, the number of pieces it has is my last consideration. When comparing weights of multi pc rods the more ferrules and ferrule wraps you have will increase the weight of the rod.
I like a multi pc rod with an even number of pcs, something that breaks down in the middle ie: 2-4-6 etc.
Frustration sets in when I am anxious to get on the water and I am still by the car trying to assemble a multi pc rod.
I read comments somewhere by an expert that the ideal number of pcs for a multi pc rod was 3...had something to do with rod action and the placement of ferrules.....Who knows?