Laning with LD is similar to any other carry’s with the exception that you can constantly harass the enemy hero. The early game is very passive, you just want to get as much farm as possible. Getting a lucky kill with the Bear’s Entangle, however, is certainly possible if an enemy overextends.
MAJOR:
A bear? A rat. Spirit Bear destroys buildings very fast from very early into the game. With an Aghanim’s Scepter, the bear can also split-push without any threat to the hero.
Strong laner: Combined with the bear, LD has high attack damage and can last hit/deny very easily. At level 5 you can also pose a serious threat to the enemy laner with the bear’s Entangling Claws.
Strong at all stages of the game: The hero is extremely hard to kill in his True Form, the bear is also very fat at the beginning of the game and both of them can use Savage Roar as an escape tool. The bear is also a 3000 HP Radiance carrier making it very strong in the mid game. While the Bear build falls-off in the late game, the hero build makes you into a powerful high-range carry (similar to Sniper).
MINOR:
High MS: Very high movement speed.
12 items: No other hero has a minion that can use items which makes the hero rather unique to play. It gives you some freedom to strategize with items, but more importantly, it gives you brute late game power, if you find yourself in a super long game.