[MultipleParadox]

I have that barrel in mine
(the esd)

It is slightly longer, by a few mm I'd say (I haven't compared them)

I can't really talk about accuracy improvement as I haven't gamed it much (either with the stock or esd barrel)

I am under the impression it shoot a slight bit more straight, but it could all be in my head for all I know. Especially considering the mp7 is pretty accurate already when stock..