REACTION First of all, Sub Boost is just great on bioroid ice - especially Eli 1.0. Of all the non-barrier ice, broiled is probably where this goes; however, the "Host ice gains barrier" drawback means Corroder gets that much more efficient for the runner, so I'm not looking to install Sub Boost on things like Neural Katana or cost=strength ice like Data Raven.
OPPORTUNITIES Instead check out some interesting interactions that take place on existing barrier ice. Sub Boost adds stability to the disappearing subroutines on Hive which should be on the board long enough to get Sub Boost installed. Snowflake magically becomes a very odd piece of ice to encounter, and if TMI was worth the risk to rez, then why not beef it up.
ALTERNATIVES The best candidates outside of bioroid and barrier ice are those with uniquely efficient traits: Hunter for its large strength/rez cost ratio or Architect because it can't be trashed. Changeling might require an FAQ update at some point.