I purchased my Islander Jive only a week ago and have paddled over 25 miles. It's not going to keep up with 14' plus boats, but it's great for easy going trips on sheltered bays and rivers. The drop down skeg is a bonus and really helps keep the boat straight. The dry hatch is simple but effective. The simple seat and back rest are plenty comfy for 2/3 hours, by which time I need a break anyway. Based on the Dagger Blackwater 10.5, it's around £200 less, and I don't think the more fancy seat is worth the extra.
Overall I love my Jive, it complements the Islander Fiesta the wife has, and being fairly short both boats sit easily on a normal family hatchback