I have the LP with Time After Time and it sounds quite good.
I would expect the quality of that release (Jazz door 1257) to be inferior. I suspect that release is an inferior live copy of one of Miles' later concerts. I have a similar release (Miles Davis - In Montreux) from the same label and while the performance is good, the quality leaves a lot to be desired. To expand on some of the other posts: the studio version of Time After Time that Miles recorded can be found on the You're Under Arrest album. The sound quality of the LP is excellent and I suspect the CD is decent. If you purchase it on CD, look to see if its been remastered. For a live version of Time After Time with excellent sound quality, check out Live Around The World (Warner Bros). In fact, every track on Live Around The World is great.