I've only had one experience with them. It was neither good nor bad. I purchased 5 Sprinco guide rods at an amazing price. They ended up being backordered for 2 weeks. When I received them, they were not guide rods. Instead, they were guide rod plugs!
I immediately called them and pointed out the error. They stated that whoever posted the items on the web page failed to mention it was just the plug for the corresponding guide rods, and used the MFG's description (which was for the guide rods themselves).
They overnighted me a Priority shipping label for the return of the items and I got a full refund within 5 days.
So, my review is mixed. The customer service was wonderful and their prices are very good. However, their web site, follow up, and inventory is questionable...