I don't think that Raven or TPM have ever done business with West End, but, rather, are two people who buy large collections and are trustworthy. I can vouch for both as well having bought from and sold to each multiple times over the years, as well as collaborating on larger deals. They would be good people to reach out to if you want to unload your entire inventory in one shot for a very fair price and through a very easy transaction.
As for West End Toys, I've sold to them before, but never used them for consignment. The sales all went pretty smoothly given the size of the transactions. I've heard mixed reviews on the consignment side. I suspect that it is a good service for certain types of sellers, but not for everyone. The people who I know who had bad experiences were all people who had the capacity to manage their own sales, but went the consignment route because of the perceived ease. At the end of the day, the complaints they had were all rooted in their lack of control over their inventory after consigning it.
I talked with West End about consignment a few years ago, but it didn't make a lot of sense for me given the infrastructure that I had already built up to move inventory and given that I'm way too Type A to be comfortable giving up the amount of control I would have had to have ceded to them to go down that road. There are some benefits to doing business with them that you won't find elsewhere (e.g., information sharing, opportunity to participate in special deals).
It really comes down to what you're trying to accomplish.