Think about it as 600W Titanium = 650W Platinum = 700W Gold = 850W Bronze = 1kW weird cheap stuff (not exactly this way, but in the end, this is close to the user's experience). Also, the new high-quality series have a short-time peak of double the rated wattage. If you pick something good quality, it will probably have a 10-year warranty and semi-passive cooling. High-quality PSUs typically run at lower temps. No spinning fan = less dust.
I had a high-quality 1200W PSU giving up after a few years. This is electronics and everything may happen.