Personally, I've only used B&H, local camera stores, and also Amazon for one camera body where they had the best price including shipping. If I need advice from a retailer or need to handle the camera before buying, I only buy the camera body from local camera stores. I don't think it's fair or moral to shop the local camera store first to get advice or try the camera out, and then buy it from B&H because B&H charges $100 less.
If you want to know whether a particular web retailer is honest (and there are still way too many in the photography business who are NOT honest, and some of them buy multi-page spreads in the photo magazines and get listed in the mags' quality-sellers programs, so you can't go by that as an assurance of honesty), check out:
Don't just look at the overall ratings a retailer gets. Read the comments, but remember that some good comments may be planted by the store, or by customers who were offered a discount by the store; some bad comments may be planted by competitors. Look for overall trends. Are there a sizable number of people saying something like: "I submitted the order and everything seemed fine. They sent me an email saying I had to call about my credit card. I called and they pressured me to buy an accessory package. When I said I didn't want it, they said the camera was on back-order. That was six weeks ago. Meanwhile, no camera." When you see a bunch of comments like that, you know it's not an honest operation. You have to use your head and not your heart; ignore the lower price quote from dealers like that and not order from them, because they simply aren't going to honor the price they quote. Any dealer that comes in more than about 10% lower than B&H or Adorama on a non-clearance item is suspicious, because that's the profit margin (or more than the profit margin) that the largest retailers can get, buying wholesale. If they quote lower than that, they have to make it up someplace else, and you won't be happy when they do.