I have a Pit Boss, it makes very good Q. I just smoked a couple o butts for my wife's office. They were delicious. I like mine for smoking anything. Pork chops, pork steaks, ribs, pastrami, fatties, chicken, meatloaf, stuffed burgers, meatballs, potato skins, bacon wrapped tator tots, jalapenos, pizza, all kinds of vegies and other things. Since you have a Weber, you can sear with it. That is not where my Pitboss shines, but the newer ones have a searing area. I would say you will be very happy with a pellet grill.
Also, since you are already familiar, with charcoal, a UDS is an entry level to professional way to go and I enjoy that even more than the pellets. WSM would also be a great option but I don't have one