So in my older computer, I upgraded the PSU to a TX650 that is probably close to 4 years old now (maybe even older). I recently bought a Dell XPS 8700 that came with a Radeon 7570. I don't game too much anymore so I'm probably keeping the 7570 the computer came with. My question is, should I swap my Dell PSU for the Corsair for reliability or am I fine to keep the PSU the 8700 came with? Basically, is a 4+ year old Corsair PSU better than a new stock Dell PSU? Thanks!
7570 is fairy low power, and even the fastest chip available for the XPS 8700 doesn't consume that much. 430W is plenty.
Quality depends on who built the power supply for Dell, it is best to do research based on the UL number. Should be somewhere on the power supply. Generally OEMs go pretty cheap on the power supply.
The TX650 from 4 years ago doesn't have a very good reputation itself, actually. Though I have used them before with no issues. They tend to explode if you get close to their rated values, whereas proper supplies should be good for a little more then they are rated.