Longspur,
I don't own a longbox , so cannot say if a long box will fit in the II tho it does have a dedicated box pocket equipped with a separator to keep it quiet..I ordered both vests back before the seasons started here in the south after going to several shops and seeing other brands for myself.. I ordered from Cabelas after deciding the seat thickness was the closer for me..and glad I did..very thick and comfortable compared to others..upon receiving both taters, I quickly decided to return the III...the II just was of better quality...the III just seemed "cheap" and one of the adjustable buckles was actually sewn in upside down...was a no-brainer for me...used my new II this past weekend and was very pleased..the padded back was also very comfortable when leaning against the tree...just ordered my third one to give to my Dad as appreciation for all he does for us keeping up the places so that we may just pop in and hunt...go for it !! you can always return it if you don't like it...but willing to betcha a fat man you will !! Peace