Is the RV2-600 the same quality as typically found in Antec, Corsair, or Seasonic? The simple answer is no. On the other hand, you have a unit that has performed well for a year - it's a known good. From a power consumption standpoint, your 600w PSU with a combined 50A across the 12V rails is sufficient to run your configuration.
Do we all want the best quality parts in our PCs? Yes. Do you NEED to upgrade your PSU? No, but if you want to burn the money for extra peace over your known good PSU then that is your prerogative.