If you have really good map awareness and you have a good instinct of where to go and when, you will be successful on TF. But this isn't just baseline "I know to roam bot when the enemy is pushed", TF requires knowledge of the nuances of different lanes and the power spikes of other champions, and a good instinct for where the enemy jungler is. Personally I wouldn't play him if you're just trying to get out of bronze, silver, or gold.
If you like TF though you might actually like Karthus. Karthus' ult can actually get down to 94s cooldown, or lower, in mid/late game. Unlike TF, it only takes 3 seconds to have an impact on other lanes after you hit level 6. TF actually has to go to another lane, and usually recall afterward. Karthus will also usually do more damage in teamfights and more average DPS per game than TF will.
They both have their pros/cons, but imo Karthus provides more in more situations, especially in lower tiers.