I picked up the Grudge and it is a oil and hook monster. I'm a down and in player, but I have to move across lane to throw it.  If you're looking for something to get through and hit like a tank, the Grudge is a great choice.  I have seen a friend throw the Alpha Crux, she's an extremely solid player, and she makes that thing look smooth.  Smooth though, not hard or extreme.  She and I competed against each other, once on a sport pattern and once on a THS.  I won the sport shot, and she kicked my arse on the THS.  Saying that, it seemed to me the ball looked the same on both shots.  Of course she threw it the same in both games, but she stood the same line, and had the same target, for what it's worth.  I'm a medium to high rev player that's speed dominant, and she is a medium speed/medium rev player.  Hopefully that helps.