To give a brief rundown for bikes.
4-1 give a better top end hp but lower bottom torque.
4-4 gives better lower and mid power but lower top hp
4-2 is a compromise
This is the difference between the 3 styles.
After that you move into differences is mufflers themselves such as baffling. Wavelengths caused by different system lengths. Back pressure and scavenging from different diameters of pipe.
Then of course you have the straight pipe. Virtually useless except in all out applications.
This is a brief, rough explanation.
The ride IS the adventure. The destination is just to get gas!