I think it boils down to personal preference than anything else. Although I admit that since I have no need for one, I have no experience with longtails.
I've been car-free for several years now and prefer road-style bikes.
One is a racing geometry and is great for dancing in traffic. I have a rear rack on it and it's just fine for commuting and light-duty loads. It's geometry makes it unstable with heavier loads. It's doable, but not enjoyable.
My second bike, a Trek Portland, mates a cyclocross front end geometry with a touring bike rear end geometry. It's just about perfect. For traffic dancing it's nearly as fun as my true roadie, but it excels at moving heavy loads at a sprightly pace with rock-solid stability. It also has mounts for a front rack, although I haven't needed one.