About 30 years ago, when I made the decision to start using framing nailers and their expensive collated nails, there wasn't much to choose from; there were only two big players. The tools themselves were basic, so I made the buying decision mainly on the price of nails and who could provide the best service for the tools. I favored round-head nails and have stuck with them ever since, having gone through about 1,000 nailers since that time in my production framing business.