I'm very happy with my GSR, hopefully you will be too.
When I called Ruger about a five round magazine several weeks ago they were on backorder and the little lady wasn't sure when they'd be in stock.
So far I've purchased a five round C Products magazine from Midway. It feeds well and is easy to load but the floorplate slides almost all the way off after five shots. The C Products company seems to be in some kind of state of change and i believe I can fix it with a little judicial metal work so it's staying here.
I called Accurate-Mag on Friday to order a second five round magazine and they were easy to do business with, as long as the mag arrives as promised.
They make the magazines for Ruger so I anticipate a well made product.
I'll get a second ten round mag in the near future and then wait to see if someone makes some decent magazines out of synthetic something or other that doesn't cost an arm and a leg. I'm hoping MagPul runs with that idea.