Up until now I've always had 1 piece longbows, but have often come across situations where transporting the full length to be extremely inconvenient. I like longbows as lightweight as possible and with a minimal riser mass (without sacrificing handle rigidity), so with my last longbow order I stewed over whether to stay with a one piece or go with a 2 piece takedown. I checked out other 2 piece TDs from the same bowyer and found no discernable difference in mass or shooting characteristics from the 1 piece, so I decided on the 2 piece.
As for 3 piece takedowns that I've tried, I've found the total bow mass far more than I care for, but for others, that is exactly what they like about them. For me, if ever one day I get a hankering for a real heavy bow, I'd get something with wheels
.
Having said that, I can see the practical aspect of being able to replace limb sets without having to replace the whole bow as long as the limbs alone are considerably less pricey than the whole bow.
One other the I like about the 2 piece system that I ordered is that it requires no tools. Given my remarkable ability to BOTH lose and forget small tools, and the strong correlation between their importance and the speed at which I lose them, this is an extremely important feature for me.