Can't go wrong with either. I'd pay more attention to what Braun did in the season as opposed to the offseason, and during the season he was a top 3 player.
The only knock against Tulo is that he's gotten hurt so much. But even if he only gives you 130 games, his production so vastly outstrips the rest of the SS that he's very much worth a 1st round pick.
This is one of those things where you might as well just go by personal preference. Either player is a great pick and a great way to start your draft. It's far more important what you do with those mid-round picks.
I would take Braun simply because this year OF isnt as deep as in previous years and you can get some decent mid level SS in the later rounds. Also Tulo has been a little bit of a health risk compared to Braun, who has been solid year in year out.
I love Tulo in any format! But Braun is a top 5 player easily. That's tough because Braun is slightly the better player but Tulo will come close to Braun at least in counting stats save BA and do it in a thinner position. You can snag an Ellsbury, Cargo etc in the 2nd round easily. I would go Tulo myself but you would NOT be faulted for taking Braun.
The best there is, the best there was, and the best there ever will be!
There is no wrong answer here. I think I might give the slight edge to Braun because he will produce a better across the board. Put position scarcity and any lingering doubts about Braun would make Tulo an good pick here too.