Anyone can tell you that a privately-owned and maintained aircraft is bound to receive more direct attention that an in-service machine. It's kinda obvious. When you have a team of engineers devoted to the operation of one aircraft, then they can obviously afford to spend all their time on it, rather than only the minimum time required in order to meet service standards.
Any just how large a team of engineers would you need to employ to look after a Lightning? How much would it cost? I think HM Flying Club probably had a large team of engineers keeping Lightnings airborne.