This upgrade will reduce cost and increase flexibility, since any standardized CBC can be configured for zero to four solid boosters; this CBC will necessitate a slight performance loss for most medium configurations.
This upgrade will reduce cost and increase flexibility, since any manufactured CBC can be configured for zero to four solid boosters (the Delta IV Heavy will still require non-standard CBCs for the core and boosters). The standardized CBC will necessitate a slight performance loss for most medium configurations.