Its all in personal preference. Going with non-liner, the same stringers and bulkheads are still put into the boat as a liner boat. The head is actually dropped in as one solid piece as well. With the non-liner, you are going to have a bit more width in the V-berth, since you don't have double walls. (The liner boat therefore is a little better insulated when using AC-Heat.)
Going with a non-liner allows you to be more creative and more custom in the interior. If you want the couch moved two inches; if you want wood veneer and brushed stainless pieces in the cabin, you would go sans liner. Either boat gets you Corian countertops and steps, leatherette interior, AC/Heat, microwave, AC/DC refrigerator, TV/DVD, hot water/cold water system; if you so desire.
The liner boat, has the entire cabin dropped in one piece. All of your storage compartments, cabinets, bulkhead surrounds, and cabin walls are a solid piece, but this is not adding to the structural rigidity of the boat in any great aspect. The hull liner is not as thick as the hull. Some think the liner boat has more storage than a non-liner boat, but its all in what you want designed into the boat that makes the difference. The liner is fixed to the stringers and bulkhead in the same fashion as the piece/component built non-liner boat.
The non-liner boat may save you a few pounds too, but it all depends on your options. I heard Macklin opted for the AT Magic Cooler too, but its only for AT owners' consumption.
Some like the flowing finish of the liner boat (like Rich's, Mark's, and my own). Some like the use of different materials in the cabin, hence Steve's, Macklin's and Clark's boats.
Price is comparable either way.