Sounds like phenolics from fermentation to me. Some yeast strains have enzymes that will react with acids that can be found in the malt and create a vanilla-like aroma which is often perceived as a flavor. Also, 70 degree room temp might be a little on the high side as the temperature in the fermentor is likely 5-7 degrees higher. Ferment in a cooler location next time and make sure you pitch the proper amount of yeast (use mrmalty.com pitching rate calculator). Also, the higher efficiency likely lead to higher OG and higher FG which would leave that fuller body "creamier" impression. Finally, if you didn't change anything from previous batches, but your efficiency somehow went up, that would leave me to believe that the crush of the grains was a bit finer that could also contribute to increased extraction of the acids from the malt and the resulting phenolic.