I would personally choose the stumpy but out of the two get the hobo. While the derringer is great there are a few cons, if you over drip even so much as one drop you'll have juice coming out the air holes, the post holes are rather small and you will have a hard time even getting dual twisted 26g in there, the outside gets slick after awhile making it hard to pull the cap off and it can get a bit warm. Don't get me wrong the derringer was a great atty but now it's out classed. I haven't used the hobo v3.1 but from the reviews I have watched it looks like a damn good atty and with the two post design it will be extremely easy to build. Other good flavor attys worth looking into are the Stro Mini v2/v1 and the Stumpy both are two post, produce amazing flavor and clouds and are worth every penny.