Its obviously better with stronger creatures, and youll be able to draw two cards on your end step if you've got the thickest creature
Number 44 Language English Legal Formats Commander, Legacy, Modern, Vintage Not Legal Formats Alchemy, Brawl, Competitive Brawl, Historic, Pauper, Pioneer, Standard, Timeless Rulings (7/1/2012) Battle of Wits has an "intervening 'if' clause." This means that if you don't have 200 or more cards in your library at the beginning of your upkeep, the ability won't trigger
Its cheaper, and it leaves your opponents very dead though I would say it require you to have a board to be truly worth casting
3 at the end of each month going back as long as we have tracked the item.
No one was more excited about this than Mark Rosewater, he was the happiest I'd ever seen him (and he's generally a very happy guy)
So lets take a look at the most valuable Magic: The Gathering cards