I burn about 60% black locust here, all locally harvested. It burns well, and long. Some say its the closest wood to coal, and when you see it burn, you'll understand why. It retains its shape during the burn process much longer than other woods, including oak. It also gets this jet black textured finish, which it holds while it off-gasses. Definitely a different black look than oak and the rest of them. I load the firebox up at night with locust, and have plenty of large coals 8 hours later. If you can get it, burn it. Oh, it smells like crap when burning, so close up the stove and get the secondary going as fast as possible.
Its known as the shipmast tree, as that is what they used it for years ago. It is basically a tree-weed. If you clear a field around here its the first to invade the area. It grows very quickly, and can shoot up new trees from its roots. Definitely not a landscape tree... so BURN IT!
-- Mike