Charles: cant remember the brand, ill try and post tomorrow. and yes ALWAYS solid model.
PGGuyy: yes it goes away in time.
Im in quite a unique position as i work with me bruv(the dentist) on site who was also a tech for 10 years before leaving to train as a dentist, so i get excellent communication and feed back.
Impregum imps taken in rimlock rigid body trays, are always cast within 2-24hrs. Die stone is ALWAYS weighed, water measured and vacuum mixed, using fuji rock (best stone in my opinion).
Dies trimmed and sectioned under at least x6 mag.
Work fitted to solid. and contacts done as described above. I can say with certainty that the contacts are spot on 99% of the time in the mouth.
What we cannot control is tooth movement. This is especially troublesome with the last tooth in the arch as they have a tendency to drift so i always leave the contacts hard on the last tooth so that my brother has some material to adjust.
Another way i sometime use is to scrub the contact points on the model with pencil and then when you seat the crown the areas will mark for easing. The trouble with this is you get no tactile feedback from pulling a piece of tape through, so there is a tendency to over ease.