Good question! There are SO many things to think about, that really by the end sometimes I think many of us end up aware of so many details...way more than the average person, even your average contractor...etc. I just measured my pullouts. As cyycdm stated, my drawers are only 22" long, but DH installed them (we did most of the kitchen DIY), and he placed them further back (than you see in her photo). They are full extension, so you can still access every square inch, but being a bit further back allows for extra stuffing overflow of bags, etc on shelves! LOL My frameless doors don't completely clear the sides of the cabinet frame, so the carpenter had to supply 1" bumpers for the side where the door is attached, so the drawer can clear the door, I'm sure you need the same thing, only in framed, you will need those bumpers on both sides, so a loss of 2" there. My slides only take up 1/4", so there is a total of 1 1/2" wasted space, my pullouts are 15 1/2" wide for an 18" pantry. Believe it or not these had to be built 3 times before they fit...no wonder my kitchen company went bankrupt (the day my new granite was to be installed, BTW) I would question why so much space needs to be lost, that seems wasteful to me.

The thing about a pullout pantry is that there's restricted access to the middle. I think 12"-15" is ideal, though 18" isn't out of the question. It might mean moving this or that to get the other thing, but can be done. That's assuming that you can access the pantry from both sides. 18" is definitely the limit if you can only get in from one side. Looked at the other way, 18" is about the narrowest cabinet that's comfortable to get into with your arm extended to the back. If you go with the pullout, it might make sense to do a full height one, or a pullout on top as well as bottom. Roll out trays are much easier to use, especially for lowers, than pullouts because you can get into them from above rather than only from the side. What they have better than drawers for a pantry is the ability to see in over short sides, and the ability to see all the trays in the cupboard at once rather than having to remember which one has what in it. If I were in your situation, I'd check to see if there were any difference in the size of the tray between the pullout and roll out. I have a feeling (which I'm assuming was created by something I learned along the way) that there might be more tray space in the pullout. If not, then it's not a matter of how much you can store but how easily you can get at it. So, if you have roll out trays, where does the door go? Do you have a 90" hinge? Most Euro style hinges are 90 degrees. Which means that the door is blocking on side of the trays. Perhaps you even have a wall there? I have 170 degree hinges, but those are big and can also can interfere with what's inside, which could be a problem in a narrow pantry. But even with a 90 degree door, you can get in from the top. Plus, it's easier to get into the pantry to retrieve something that slipped over the side. With the pullout pantry, you might want to get a trigger gripper, which can be helpful. Just remembered what might tilt it decisively to the rollouts: You can put more roll out shelves in a pantry than you can trays on a pullout. Because all the trays on a pullout come out at once, you need air space between them to get stuff in and out. With roll outs, you can have trays that are one can high, or one box of X high, and have only an inch margin to the next tray up. In that way, you can fit a lot more in the same cupboard.

Definitely walk in if you have the space in your floorplan (especially for new construction). With the walkin or reduced depth pantries with doors everything is visible and you can plan space for brooms, infrequently used appliances, and bulk storage. Walkin pantries have standard household doors which will last for decades. Downsides of pullouts are that they can move abruptly, which can cause items to shift or tip over. They are also are more fragile since the glides bear a lot of weight even with reinforcement. I can certainly imagine restless kids or grandkids slamming the pullout pantry closed or trying to climb up the shelves like a ladder.

"I think the premise is to have pulls be *no more than* 1/3 the drawer length." I think designers invent "rules" like this just to have rules. I have never paid much attention to such nonsense. There is a limit, of course, to how wide pulls can be. You don't want them to interfere with drawer operation. Other than that, anything that looks good to you is just fine. As for variations in length, don't worry about it. There is no rule that all pulls have to be the same size, although the same general design is good. One thing about pantry pulls. You are probably going to be opening pantry doors with arms full of groceries, so a pull you can operate with an elbow, wrist, knee, or one pinky finger is a good choice.