I dont know exactly, whether it is worth or no.For me it is, because I like to play with things, I like do modifications. It is not so much work to modify the airbox and the inlet rubbers, it just take time.
Both kits works with open air filter and slip on, just the MB kit requires mentioned modifications and it also works with full exhaust system including 4-1 headers.
So, I would say it is up to you what you want.