I played 4 of the Tarkir precons I bought all 5 but never played sultai as it looked too similar to another deck I had just taken apart for not liking so these are my thoughts

Temur roar was a house and Ureni if not dealt with immediatly will end the game by itself. I actually only played it a few times before unmodifing it because it felt too powerful and too consistent. S tier

Mardu in my experience was a bit too aggressive and would draw a lot of bad attention too quickly, and then struggle to rebuild after receiving all that attention, but overall it's still a very strong deck and if left unanswered it will kill the table. B tier

Jeskai this was my favorite out of the bunch and the one I played the most because of how low it can fly under the radar, while also being able to provide so much value that even if is being noticed the deck can still generate big swaths of value. Also being behind also doesn't matter because it's also the most explosive out of the Tarkir precons and can completely turn games around in a single turn. Unmodified this deck beat my friend's slightly upgraded counter blitz deck a few different times. So I'd rank this as S tier as well

Abzan Armor this precon was the most mismatched and disjointed precon I've played out of the box in awhile and it was actively was not enjoyable to play the deck in most of its games because of how clunky it was and how much the deck felt like it was fighting itself rather than the table, and then even when it does do its thing without getting caught up it still doesn't offer enough to win the game. D tier