3 problems with Dragon:
1. It spawns too early.
2. It's too easy to kill, especially too easy to solo - definitely needs a debuff on the enemy it attacks, like Summoner's Rift dragon.
3. Its spawn location is way too defensible. It's easy for the other two to camp outside of dragon's spot and defend one person soloing it. You basically have to suicide to contest the dragon.
I think the whole top jungle on TT could use reworking so that Dragon is at the very top of the map and is much less easy to secure and defend. The team that gets to Dragon first typically gets the Dragon, or gets a couple kills when the enemy suicides to steal it.
edit: Let me expand on this some more. The reason spawning too early is a problem is because it heavily favors team comps who are capable of winning an early dragon fight. Remember when there was level 1 dragon on Summoner's Rift, and basically there were only 10-15 viable champions in the entire game because they were the ones who were good in level 1 team fights? And TT dragon gives you a much bigger boost.
I find it absurd than anyone could argue TT dragon isn't too easy to kill/solo, considering it's weaker than the SR dragon which isn't even the main NPC objective, and gives a reward comparable to baron - in fact, at level 18 it's probably better than baron because 18% bonus damage is HUGE for such a long buff.
And for the position, I find too many long TT games devolve into both teams camping around top jungle, because if you leave the enemy team will sit themselves in the brush, kill your wards, and you'll be at a big disadvantage for the dragon fight because your lack of vision gives them a free initiate when you go to stop it. Again, another SR parallel for something that was fixed on Summoner's Rift long ago: the brush outside of Baron. It made whichever team got to Baron first win the fight and often the game.