I'm not sure any of the boutique 300B's fall into warm category anymore. Based on many reviews seems all are more in neutral camp, not trying to sound cool or warm. I can tell you the Acmes in this category, have natural timbre, but not warm and round.
I've noticed over years the golden glow sound is an antique sound, Today's preference is neutral flavor, natural timbre will not require one to seek warmth. I believe any of the modern boutique 300b's will be noticeable improvement over your present tubes. Now, if you're looking for rounder, warmer bass, full mids and rolled off highs, I don't know that any of the boutique tubes will give you this.t.
Tubes that provide natural timbre will not have you desiring more warmth. I'm quite sure the Acmes, and the other top tubes will make your present Gold Lions sound washed out and grey in comparison.
