When designers were asked to develop the ship that eventually became the Delta-class JV-7 Escort Shuttle, they were pointed to the original Lambda design and given a list of desired improvements. The Imperial designers threw out the suggested improvements given to them by the commanders and instead began interviewing pilots of the Lambda Shuttle. They collected first-hand reports of performance shortcomings from those most experienced with the ship's capabilities.
Aside from faster sublight engines and stronger shields, the new design also boasted a reinforced hull to improve the shuttle's chances of reaching safety undamaged. The Lambda Shuttle can defend itself, but the Delta-class has better manoeuvrability and far more respectable firepower: three heavy forward lasers in the front, a turbolaser turret covering its rear arc, and a pair of concussion missile launchers, making it extremely dangerous for any pursuer.
What caught the attention of organizations still using the Lambda Shuttle was that it still has a slightly better cargo capacity in comparison to the Delta-class; within secured sectors, the Lambda Shuttle is still an attractive choice over the more expensive JV-7, explaining why the Lambda Shuttle has not yet been entirely replaced by the newer JV-7. For more hostile sectors, the Delta-class, with precious passengers and cargo on board, is the obvious choice over the Lambda Shuttle, as it can get its passengers safely through hostile areas where the Lambda Shuttle would be unable to grant its passengers the protection, manoeuvrability, and firepower often needed to reach its destination without fighter escort.