This is purely an ascetic issue but on the AK 101, 74 and 74u since they feature the russian style muzzle break the suppressor when attached is hanging off the end of it rather than going over or overriding the muzzle break.
Inclosed are some images showing the difference. Again purely cosmetic but for firearms lovers like myself the extra effort really is appreciated.
Also the handguards are backwards on the AK series of rifles.