I have no personal experience with Beachcomber. From what I've heard, they are a decent product. Generally speaking, I would consider the Jacuzzi to be a better brand/product.
Only you can decide on whether the J300 jets feel better than the J200 jets. For me personally, I can tell the difference when I sit in a premium model, then a mid-tier model and then an entry level. If the J365 is within your budget, I would wettest and decide for your self. Usually, the longer warranty comes with some better components and other upgrades. I cannot ever recall having a customer wish they bought a less expensive, more basic hot tub.