As long as you tumble your coins before spending them on drugs, there is no difference in the anonymity of multi-sig wallets versus centralized escrow. Anyone who says tumbling doesnt work is full of shit, and that includes you /u/Vendor_BBMC
Bitcoin by design is not anonymous. Every single satoshi can be traced on the blockchain back to the very beginning. This is why proper tumbling involves complete seperation between the pre-tumbled coins and the post-tumbled coins. You do not need to take either my or BBMC's word for it. Due to the magic of the blockchain, you can do a reverse taint analysis on your tumbled coins and see if you can find your pre-tumble wallet in there. If not - boom! Your coins are clean. Now it doesnt matter where the hell you send them.
This should be your goal for every single transaction. Do not trust that your market has some super secret squirrel bitcoin tumbler. Do not trust them for anything. Any market that insists on using centralized escrow is waiting to steal your money. The only reason that /u/Vendor_BBMC is an advocate for centralized escrow is because he DOESNT FUCKING VEND ON THE DNM. Whenever you hear one of his meth-fueled rants about anything pertaining to the DNM, remember that no one has ever even tried his shit. For all we know, he's some pasty wanker in his parent's basement. Any vendor who was burned by SR1, SR2, C9, Sheep, Evo, Agora, BB, MeM, and others will tell you that centralized escrow is designed to scam vendors and buyers alike.
The cycle will rinse and repeat until buyers and vendors alike demand 2of3 multisig with timelocks on every single site. I ain't new to this battle. Look back at my history and you'll see that I've been advocating multisig since fucking TMP. TMPSchulz (or whatever the fuck his name was) new what was up years ago, and his market was still the safest and most reliable in the history of the DNM. It's only because we couldn't pull our collective heads from our asses and walk away from SR2 that TMP fell to the wayside. And look what happened: the feds stole that juicy fucking escrow AGAIN. Hardly a fucking year after they did the same thing to us with SR1. Mult-sig = no juicy pot for the feds. The benefits far outweigh the "hassle" of tumbling, which we should all be doing for every single transaction anyway.
BBMC may be a meth god but his understanding of much technology is laughably bad at best so its good that he sticks to what he is comfortable with actually. His opinions on PGP and MS escrow are tragic but I think surespot is fine at the moment so I wouldn't knock him for that.
I'd say listen to anything meth-related or vending-related (non tech stuff) as gospel and keep the rest at a good distance.