The problem with Eminem's production (in his prime) is because of his lack of musicality, his beats usually sounded like something only he would rap over. That's not a problem when you're self-producing, but when you produce for other people, you want to give them something tailored to them. That's what Premier was referred to as by Guru, a beat tailor. It even worked for Aftermath artists (50, Obie, Game), but then you give those same beats to Nas or Jay and it doesn't sound like you made them specifically for Nas and Jay.
Heard Superman recently. shyt still slaps
The Eminem Show had some dope production on it like this one, "Soldier," "Sing for the Moment," "When the Music Stops," "'Till I Collapse." Usually, Eminem saved his best beats for himself, but he could give dope production to others ("Patiently Waiting," "shyt Hits the Fan," "Runnin'," "We Ain't").
I think "Smack That" is one of the few Eminem beats that were given to someone else and it actually became a big hit. Akon doesn’t sound awkward on it at all.