Buses are ok, not always according to schedule but so frequent during the day it hardly matters to me.
Trains are a bit of both:
- most regional ones are brand new
- the other aren't to bad either: old fashioned but clean and well maintained. In fact a number of commuters prefer the older ones.
- they are expensive (if you teamed up with three others you'd finance a Tesla in 10 years I guess. The downside is you can't expect everyone to go to work and home at the exact same time every day or even stay in their job for ten years)
- while they might be reasonably precise for weeks on end it is never a surprise when they are delayed.
- information is poor (my guess is because they have to pay alternative transport if they are more than 30 minutes delayed so they'll try to avoid announcing delays as long as possible. Again this is just my guess.)
- the commuter trains are always crowded in the Oslo area. Sometimes they are so crowded you literally cannot move around. Having seen and read about stadium fires and other disasters involving crowds I wonder how this is even allowed.