OK, I looked at his website.
Tanner's molds are made from brass.
Lyman, I think are made from steel, some are hard to find.
Lee molds are made from aluminum, I think.
I have heard that the Lee molds don't retain heat, and that Lyman is better once it is hot.
What is the advantage of brass? I would have thought brass would have too low of a melting point to make a mold for lead.
I have molds consisting of all 3 metals that you mention.
Lyman molds are steel, slow to heat up, and slow to cool down, and one must buy the blocks and handles separately, or switch a pair of handles (ya already have) between different mold blocks.
Jeff tanner brass molds,.... no, you don't have to worry about brass blocks melting at molten lead temps. Tanner brass molds are good quality blocks, but come without handles or a sprue cutter. Large Lyman handles do fit Tanner blocks, not sure if their small handles do.
Both Lyman, and Lee molds, come with sprue cutter attached to their blocks,.... Tanner blocks require an extra step to the casting process by requiring sprues to be cut after casting.
Lee aluminum blocks heat up fast, and don't cool down fast enough to cause any sort of problem once a caster gets his "casting rhythm" going, in fact I (personally) can cast more "balls per hour" with my Lee molds, vs, either my Lyman or Tanner molds.
If I take a break during my casting, the aluminum blocks do cool down rather quickly, but they ALSO heat back up to molding temp, just as quick.
Sometimes, mold prices can be a concern for a new caster, when also pricing other things one needs to cast with.
The balls Lee molds cast, are just as good as the other brands of molds, and will do it for less money.
Sure,..... (before anyone says it) my Lee aluminum molds are softer than my steel or brass molds,.... but I don't use ANY of my molds for a "hammer", so they perform just as well for me.