I made my mind up. I just sampled a beer that has been very good to me, made w/ S04 under temp controlled conditions. I adjusted it slightly using S05 instead based on a tip from a friend.
Well. I've never had a dumper, and this is drinkable, but it's only that. The beauty of the beer made with S04 is gone with S05. The beer does nothing well. I'm hoping that a bit more time conditioning in the keg might help, but it's been 22 days since brewing, and the S04 beer was always terrific by this time.
So--S04.