which are better quality Deerfield cabinets or Fairview cabinets

Neither.

Melamine,mdf,knock down and RTA should never be used in the same sentence with quality.

My cabinet interiors are melamine. I was very unsure about this, but so far, so good, and they are very easy to wipe out to keep clean. I have Shiloh cabinets. If you want a wood interior, I believe Mouser does them - significantly more expensive than Shiloh.

There is nothing wrong with MDF or plywood depending on where/how it's used. MDF is often used for Shaker doors as it does not warp and is less moisture sensitive with the painted finish. Plywood cabinets (usually 3/4) are virtually indestructible.

Most people on GW are obsessed with Blum hinges and slides, and they are a very good product. I decided not to do the upgrade to Blum on the recommendation of my KD - said they had had zero problems with the ones that are standard on Shiloh. After over 18 months, I have no complaints and I have some very wide drawers with lots of heavy pans.

You certain want drawers that open all the way. I've always lived with old kitchens and were unaware that in the last few decades, kitchen drawers often only opened half-way. Huh? Mine open all the way.

I liked Shiloh as they had no uncharge for full inset doors, which I used for my upper cabinets. I like the traditional look and it fits with my house. I used European for the bottoms as I wanted every single bit of real estate - I have a LOT of stuff!

You should see cabinets before buying.

I found an article that was great. Good cabinets:

1) 3/4 inch plywood construction drawers, boxes, doors

2) Dado joint between side and rear.

3) dovetail on the drawers

4) higher quality (furniture) grade plywood

5) bottom vs side mounted slides

Here is one example that discusses it. You can do a google search and find abbreviated lists.

http://www.home-style-choices.com/kitchen-cabinet-quality.html

Here's something I wrote some time ago that's pretty thorough. Methods of construction and quality control matter more than a specific material, your mileage will NOT vary.

FWIW- very few cabinet brands use MDF for boxes except for some as "Paint Grade". May will use MDF or veneered MDF for center panels on doors.Many use particle board which they like to call furniture board (what I think about that is in what I wrote but suffice it to say that my own kitchen has particle board boxes with vinyl interiors and going fine after 14 years) There are a lot of salespeople that will use the term MDF instead of furniture board or particle board because they don't know any better or because the public takes better to it than to the alternative.

Oops, forgot the link

https://www.houzz.com/discussions/cabinets-low-to-high-oh-my-dsvw-vd~2426671