Sorry to be the newb fretting over simple issues, but I appreciate insight from those with more experience.

I've put 4700 miles on the chain that came on my roadbike. While cleaning the chain recently after a sloppy ride I noticed a subtle noise about every 4-5 links as the chain circled the cog. Sheldon's site led me to measure the chain and sure enough I've got at least 1/16" of stretch. Time for a new chain (or maybe past time). My bike (Giant FCR2) came with a shimano HG-73 chain. In looking at reviews of this particular chain I found many reviewers complaining about quality. Some claimed breakages (multiple) inside 1000 miles. WTH.

Am I safe replacing my chain with another HG-73 or have I just been unusually lucky with this one?

Can you upgrade a chain? I put a lot of miles on my bikes and I'm not very handy! Would this be a good place to spend a little extra?