Whilst the casualty doesn't care what colour helicopter comes to the rescue, they might be concerned that... no-one comes at all because a reduction in capability was accepted at risk.
...and the difference between this and using ageing Sea Kings with increasingly poor unserviceability rates is what exactly?
Oh and before you say it... Carson blades and a new gearbox are not the gold plated solution to the causes of all unserviceabilities - ask the Navy.