We had a ESRI tech here several months ago. He mentioned that at 10.1 SDEGeometry was the default. He didn't give us an exact "when date" as much as he said SDEBinary wasn't the future. SDEBinary is still available at 10.3. He also said we should expect a "big" increase in performance when we migrated to SDEGeometry, but that hasn't proven to be true for us.
At this point, the biggest issues we are working on related to performance are: 1) maintaining our spatial indexes and 2) large SQL spatial views (200,000 + records) created from command line tools.
ESRI's rebuild indexes tools don't appear to work on SDEGeometry spatial indexes so we have to manually rebuild them every couple weeks to maintain performance on large feature class that are regularly edited.
With large SQL spatial views, we see VERY poor performance when trying to snap against them while editing. As a result, we are scripting all of our large spatial views to output as separate feature classes. We don't have a solution yet for creating the spatial views after command line tools go away.
When we were using SDEBinary, we saw better overall performance and we didn't have to implement any of these work-a-rounds.