My preference is always for the rolls. You can cut the size you want. There will still be some waste. But I use that waste most of the time to make battings for smaller quilts. I do like to have a wide roll, 120 inches on hand, as that will work for most of the size quilts I make. As the batting is 120 inches wide, I usually cut the batting for the width I need, using the 120 inches for the length. So how many quilts you make out of a roll really depends. If you are making small quilts less than 60 inches wide, you can sometimes get two quilts out of the width. I also like having a smaller roll on hand like 96 inches. Cutting batting and using it off a roll usually goes much smoother for me as I don't have to deal with most of the fold lines and sometimes stretched places of bagged batting. I have had a very stretched out king sized batting that had such distorted stretched out places, I actually ended up cutting out a section and putting in a sort of dart. I like to mark what a left-over piece and the size is. I have made franken batting with just a couple of seams out of the cut offs sometimes and have used a lot of it in lap quilts. The downside is the shipping as that can be expensive, you also need a place to store the batting, and cutting it. I am lucky as I have a room that I can store it in and for cutting the length, I just have two old dining room chairs with slat backings that I can put an old shower rod through and place the batting roll like a roll of toilet paper. I then just measure out the length I need with 120-inch tape measure and mark the line using roller chalk and a straight edge (I use an unused length of wood trim for floorings I had laying around.) I think you could also just snap a chalk line across the batt too. Also, the batting the from the roll also ends up being squared up as packaged batting can sometimes be a bit lopsided and you really have to measure the size too.