I've used hcl, and it give a pretty clean product after washing with dry acetone when salting out of limo with hcl water. However, I've heard you shouldn't use hcl with limo, something about it reacting with the limo to form some kind of nasty byproduct.
In the future I plan on using vinegar or fasw, then freebase again and salt out the hcl using dry iso/acetone with the freebase mescaline in it. HCL is really where its at with mescaline for me, fumarates are cool too, but usually end up with excess fumaric acid, acetates always seem hard to dry, unless you clean them up a good deal. Hydroscobic alkaloids I'd be willing to bet, but i get that with hcl's too, they just wash up easier than acetates which are more soluble in dry alcohols used for washing.