Ah, you sound like a man that is in the afterglow of a Macallan Finish.
Your description is very much like my own. As far as my experiences with the older beverages in the Sherry line:
18 - The complexity goes up, there are a lot of flavors and spices that come into play, but they are very well integrated, and the finish is refined. The dry nature (I think from the Sherry) is gone in this expression.
25 - Balance, everything is very well balanced, deeper and richer textures, and the finish, Oh, my G*d the finish, 20-25 minute finish off of a dram, and I love every minute of it. Something special about this dram just makes me happy...
30 - Dominating, there is something about the 30yo, maybe it is the wood that is really starting to dominate in this dram. It is not as well integrated as the 25yo, but great mouth feel and finish make up for a lot.
Cheers,