Nothing special other than not factory production barrels and the 17 Hornet is a wildcat. The barrels were made on the same equipment by the same people out of the same quality of blanks as their production barrels are. Even so they will both be good shooters and the 17 about as much fun as you can have with your clothes on.
Pay attention when you b uy dies as there are two different K Hornets (17Kilbourne and 17KE Kimber/Ken Howell) and either may be much harder to find form and load dies for than the more popular 17 Ackley Hornet. Shoulder angle is the main difference between them, but if I remember the K's are also a little longer to the shoulder than the Ackley.