CO had one for a few years about a decade ago. It really did separate the men from the boys. The TD provided 28 oz Hammers, and that's all you were allowed to use. Distance/stadium balls were used on 300'. fields. Unlimited HRs. Very few were hit. It takes a Ruthian swing to put one out with a Hammer.
Interestingly, .52 300 balls are quite a bit easier to hit out with Hammers. The ball does much of the work.
Obviously in today's age of sissy men, this tourny fell by the wayside and few teams signed up for it.