These cabinet doors & drawer fronts are all veneered. We don't manufacture any slab doors in solid wood because wood expands & contracts too much which would cause warping & twisting. I hope this helps! Thanks for your inquiry.

Is this because it is a slab style and would it be different if it where a 'shaker style' ? Longevity and repair wise, which is better?

Yes, these are veneered because they are slabs. If it were shaker style it would be solid wood. As far as repairs, solid lumber is much more easily repaired than a veneer door. Longevity is hard to predict because so much of it depends on the environment of the cabinets. Both veneers & solid wood can have a very long life span if properly maintained.