I got hit by an almost two hour delay last Friday. Suddenly the marginal benefit of lounge access seemed very useful.
As the policy at work is economy class flights for under 6 hours and business class for over, the easier check-in is also a nice benefit. Although, since the advent of self-service check-in, that has been getting smaller.
The miles/points are of limited benefit. Given that I fly for work almost every week, the last thing I want to do with mu leisure time is get on a plane.