When the Penn 70's first came out about three years ago, I bought a pair for my wife, who is one of the premier stand-up marlin fishermen (or women) in the world today.
She loved the reels, but we had two occasions on big fish, where a screw would back out of the drag plate, causing the reel mechanicism to freeze.
On one of these occasions, the line broke, and she went flying across the deck and landed hard on her back.
When I contacted Penn, they acknowledged that the reel had "some problems" and to send them back in for an "upgrade". We have not used them since, but will try them again in Cabo San Lucas, eight weeks from now.
I hope they've solved the problem.