I just went switched from a Hellcat Pro to a X-24 MFK edition recently and I am very pleased with the X-24. I did like the Hellcat Pro also but the X-24 is a bit louder and the remote has a few more usable buttons and other features I like and am still getting used to.the main reason I made the switch when I did is my son was looking for a call and my hunting partner had the X-24 MFK edition with like 300 additional MFK, Tony Tebbe and Bustin fur sounds on it and it was less than 6 months old and he offered me a price that was WAY to good to pass up. Bottom line is they are both good calls it all depends on how much volume you really need for your area and how much you want to spend.
Lucky Duck also makes a pretty good call also I don't have any personal experience with them but know friends that have them and they are happy with