My sample size is limited, certainly not like someone like John B, and no, I've never used the Nosler Partition, just the general cup & core stuff before I started handloading. I am not making any judgments on the NP. I have said, repeatedly, that the NP is a fine bullet, and if I was interested in a lead bullet, the NP would be a good choice. So, I'm not sure what the issue is. I just don't want to eat lead. If you don't mind, whatever, it's a free world. You're free to do as you please. I base my choice on (a) the research done to date (b) and my knowledge of the toxic properties of lead. I have not personally noticed any detrimental effects of using the TSX/TTSX on my style of hunting, and it so happens that all three deer I've shot so far using copper have been bang/flops, with very, very minimal meat damage even with a boiler room shot at close quarters. Yes, that's a small sample size (I started handloading only three seasons ago) but others report similar results. Aside from the lead issues, I think the lack of bloodshot / pulverized meat to be a benefit of using monolithics as well. Your mileage may vary.