I think it was through a general Google search, but plenty of pages deep where I found some comments on another brand's forum that said they did get a great price (drove from a long way down South to get the deal!!), however the PDI was minimal and more of a Q&A (they had inferred that they were experienced Rv'ers to the seller) and that they had determined to use the brand dealerships for any issues as the seller was a wholesaler not like a dealer. To them, so far, it was worth it as it saved them a few $k on the sale (FW) and as they were considerable distance they didn't care about follow up.
The fact that I had to dig so deep also did nothing to instill any confidence in them
Once I found a local dealer that was within $1k of Nationals quote on their first offer I decided to go with the local guy and negotiate to whatever I could, chalking the rest up to supporting a real dealership that would hopefully be there for me if/when I need them. Fortunately for me they came within 00's but then offered all of the camping deals which thus far has saved us almost $200, plus I've still got 2 weeks camping next year for free and a 1 week camping by Disney FL to look forward to!
I also was looking for a new WD hitch and having it installed; they offered me a pretty reasonable deal that would have it taken care of while I was doing paperwork and the rest of the PDI. They even helped troubleshoot a brake controller issue on the way out for the test drive and provided some assistance in getting it set for the new trailer brakes.
I would say that if you don't care about post sale, are really comfortable with the great PDI documents available here and on the web, and are confident that you will be thorough in your checking everything and setting it up etc. then consider them. However if the price difference isn't all that great, use their quote and negotiate with an actual dealership that you can consider using after the sale. They may even match the $, but even if they don't it's probably worth that little extra knowing that they offer (hopefully) more of a hands-on sale, set up and seeing you leave safely, plus being there when you really need them approach.
This may seem like taking it too far but I built an Excel sheet that listed the 15 or so quotes I received and had weightings for things like +ve & -ve feedback, distance, included options, financing, add-on warranty & other extras pricing (they always will try to sell you stuff), willingness & costs of installed options (I wanted air vent covers pre-installed in a color of my choice), cost of WD hitch & install etc. I also asked what their typical PDI looked like and how long they anticipated it taking and made a note of that. Be sure to know whether you're getting full propane tanks and a battery with box etc. Were the black plastic container tubs under the dinette included? (I've seen some dealers charge extra or not have them present!). I put all this information into a table and created a point system!! My wife just shook her head and looked: