I don't know if all make you feel like you've been slimed. As I said in another recent thread, we had a good experience at a small dealer in Fife but they went out of business a few years later so maybe that's why ...they treated their customers well both sellers and buyers. That may give the indication that they weren't good at making money.
But the nature of consignment is kind of making the customers feel that way because they are trying to make money on both sides. Consignment does fulfill a niche as some sellers, as you've mentioned, as they do not like to do a lot of what's involved in selling their RV privately. Consignment takes the hassle out of the hard negotiations especially but also marketing and dealing with the financial interaction after the deal has been made. A consignment dealership can take trades and arrange for financing that a private seller really doesn't have the means to accommodate.
We've used both consignment and have also sold our RVs privately. Yes, it is much easier using consignment but granted, you do leave a lot of money on the table by doing so. In our case, it was worth it as we had other things going on where we just didn't have time to market, show, negotiate, etc., etc.
At any rate, the dealers I recommended in the other thread were Puyallup RV and of course, the now relatively prominent consignment dealership in the Puget Sound area located in Everett, Maple Grove RV.
We almost went with Puyallup RV at the time --this was more than ten years ago, however-- as they explained things well and seemed relatively up front. But again, the smaller dealership in Fife made us feel the most comfortable and that's who we ended up using and had great experience actually. It's a shame they couldn't stay in business.
Maple Grove has become a fairly high volume used motorhome dealership. I remember over a decade ago when they were just a very small consignment dealer but focused on higher-end motorhomes. They do have a decent reputation for an RV dealership.
You might also want to check out Kirkland RV that is also up there in Everett (weirdly not in Kirkland) as they also have a relatively decent reputation.
Again, as you know, most RV dealerships do not have good reputations and they always will have customers who come away unhappy. So you want to pick one that has the least number of those unhappy customers ...goes without saying, I suppose.
Puyallup RV
Maple Grove RV
Kirkland RV