You WILL see minute cracks where the rails and stiles meet on an all wood door, as well as where the panel is inserted into those stiles and rails. That's just how wood behaves in the presence of moisture--including your wood floors. They too will gap in the winter and potentially cup in the summer. It can be controlled a bit more if you use AC in the summer and use a humidifier in the winter, but nothing on the planet will stop it. Choosing wood stiles and rails with MDF panel will stop most of the cracking at the joint where the panel meets the stiles and rails, but it won't stop the cracking where the stiles meet the rails. If the natural expansion and contraction of wood will drive you crazy then don't get wood. Get an all MDF door that is routed to resemble a recessed panel door or raised panel door or whatever you are looking at. And then choose thermofoil if you want a "perfect" paint job too. Because even sprayed MDF will still not be 100% perfect. It's about as good as you get for smooth paint, but thermofoil is smoother and more even still.

From the attached link: Raised Panel - Solid Even though the panel is called solid, it is not usually made of a single piece of wood. Wood expands and contracts with changes in humidity, and this can cause the door to split and crack. To counteract the problems of natural movement in a solid wood center panel, the panel is usually constructed using several pieces of solid stock lumber glued together. The wood strips used to construct the panel may not all match in graining and color. As in the case of the slab door, the door's strength comes from the manner in which the pieces of solid wood are reversed as they are glued. The panel is then cut on all four sides, so the center is higher than the edges. The face of the panel is usually flush with the front surface of the stiles and rails, with the edges forming a tongue which fits a corresponding groove cut into the door frame. The groove is slightly larger than the panel's edge to allow the panel to float in the frame. This simply means that the panel has room to expand and contract during humidity changes, reducing the risk of the panel cracking or splitting. I gather from the Woodmode site that this is how they construct raised panel doors as they describe their raised panel doors as being constructed from solid wood. How big an issue the movement of the centre panel in a flat panel door will be probably depends on geography (I have seen some dramatic examples here that am sure would not be acceptable to many folks while I tend to think the hairline cracking I have seen is part of the charm and patina of age of painted cabinetry. In terms of Woodmode they do kiln dry all their wood which may in part explain why they have not have felt they would get better performance from an MDF centre panel that some companies are opting for. I also think it is a market issue a lot of Consumer's in the US have a real aversion to composite wood products regardless of the possible benefits (this does not really carry over to Europe or Canada). Cabico and many other Quebec companies offer 100% MDF doors for paint finishes (same opaque finishes are usually available on maple at Cabico). Lots of their MDF door styles are raised panel. Here is a link that might be useful: Explanation of door styles

Poorly built cabinets regardless of what material they are constructed with are going to be low quality. The material used is not the only reason for a 9k price difference. As far as the two companies listed you will find much more information on Shiloh than Century. I believe Century was founded in 2000 and is a Canadian based company. I do not know much more information positive or negative about them. You will be able to find a lot of information on Shiloh. Shilo cabinetry was founded in 1977 and is based out of Missouri. They have a solid reputation and are generally regarded as a good value. As of now there is no up charge for inset cabinets and depending on where and when you order dovetail drawers as well as soft close may be an upgrade or included as part of a promotion.

MDF is the preferred material for painted cabinets. Solid wood moves around too much, unless you have perfect in home humidity control. Then your coatings crack.