I have a set of the stock 9443 blades, and 2x sets of 9450's.
I like how much more rigid the 9450's are. The plastic on the 9443 props is much thinner and flexes a lot more. It might just be my imagination, but I'm sure in fast direction changes, and if suddenly needing to ascend while descending, that the more flexible 9443's would be slower to respond, as they'd flex first, and then move the quad second. A more rigid prop like the 9450 has to handle faster turns and direction changes much better.
I cannot comment on the flight lengths though, as my quad is nothing like standard anymore, and I've never flown a single flight with the stock blades, as my quad came with 2x sets of 9450's, and when I asked to buy another set just to be triple-sure that I'd have plenty of spares, the guy accidently grabbed me the stock ones. I wouldn't even have them otherwise. I didn't return them, and kept them deliberately though, as one day I'd actually like to compare how she handles and flies with them, but I need to get very very familiar with her on the 9450's first, so that I can pick the difference.