The problem with Vlad is his transition from early to mid game. A lot of people play him top lane and I have come to think this is a bad thing.
Early on, he is going to have problems in his lane. He will be forced to stay at his tower and farm to catch back up, which he can. During this time, the enemy can roam and help his team gank or get objectives. If Vlad leaves, he will stay a bit behind in cs and he won't reach full power by midgame and he won't be as useful. If you get teleport on him, a lot of tops will just bully the **** out of you because they know they will be able to all in you with ignite and you will have to base and lose even more cs.
Then when gankers come to help you, you have absolutely no CC so a lot of the mobile tops can get away pretty easily. Mid game, you can easily push your top tower down, but by then, the other top would have probably roamed and snowballed the game. If you overextend early to keep the other top in the lane, you can be ganked pretty easily unless you heavily ward.
I think mid is better so that you can at least get to all the other skirmishes and help. But without any real CC he will have a hard time securing a lot of kills and snowballing the game. His ganks are also terrible, which doesn't help when you roam to another lane.