I've ordered from Provident 7-8 times, they are a little cheaper and noticeably slower shipping than APMEX but definitely not out of bounds. Given that, I'll order from them again. Their packaging was weak on a couple of the earlier shipments but came up in the later. APMEX packaging is the top, even for small shipments. Almost irritating when you're forced to consider a chain saw to get at 10 oz of silver. Before a major order with anyone I recommend trolling the sites to see if there are reports of problems. That'll keep you from becoming one of the victims of a Tulving type disaster. Clear signs of major financial difficulty were apparent for the better part of a year to anyone who took the time to look. I got screwed for a lot of money in my first major PM buy, but that was before the internet era.
http://golddealerreviews.com/ is a good source to read reviews. There are going to be problems with any company, I judge them on how they handle the problem. The packaging on the Provident shipment I mentioned was negligent with the bars making the box bulge at the top and no padding was put between the bars and box or the bars and the coin tubes. Provident charged enough on the shipping to have used a larger box and a lot of packaging, but someone either got cheap or lazy. And Provident wouldn't do anything about the damage. For me, Apmex passed the customer service test, but Goldmart, Provident and Gainesville failed. Everyone has to decide for themselves what premium they are willing to pay for acceptable customer service.
I've order four times from JM Bullion. The first two times were fine and dandy. The third/fourth (combined orders) they contacted me about me not sending payment (they wait ten days). I replied that day that payment was sent... no reply. I then sent a follow up with a picture I took of the certified receipt from USPS... had a reply that payment was found. No idea why the delay or "lost" payment on their end. I have ordered once from APMEX. No issues. I bought from them because I ordered coins that JM did not have. Ordered a couple sets of Austrian Phils. I know people on here say to not order coins from APMEX but I had no problem(s). When the 2015's Phil's come out, I'll probably buy them from JM Bullion because they tend to be cheaper there (free shipping vs. APMEX's pay for shipping). I'll order from JM Bullion again. I'm in the USA for those wondering.
I never personally ordered from APMEX due to the huge premium that tack onto their items but I have heard a lot of good things about them. I will most likely use them at one point or another because I love their stackable 10oz/100z bars.
