I have several of them. I generally like them, though some performances are edited, for some reason. For example, the Beatles' 'Help' is missing one verse. I know they performed that verse since it's on the recently released set of the Beatles' Ed Sullivan appearances.
There are other times where the songs are shortened but that may have been the way they were performed. And quite a few of the performers lip synch the songs (or sing over a recording) but this was how they were originally performed.
However, only the first 4 discs are currently being sold separately whereas Time Life sells all of them separately. So it depends upon if you want the entire set or just a few volumes. I'd probably get volume 5 (Temptations and the Supremes) if they ever offer that one separately.
As I said, I generally like the ones I have, but be aware that some performances are not complete.