There is also a ~5x increase cost in memory utilization for any implementations or implementors that use or wish to use in-memory storage (yarnd does for example) and equally a 5x increase in on-disk storage as well. This is based on the Twt Hash going from a 13 bytes (content-addressing) to 63 bytes (on average for location-based addressing). There is roughly a ~20-150% increase in the size of individual feeds as well that needs to be taken into consideration (on the average case).