We also carry some sections that the referred sites do not. Most importantly there is Garbo's scientific astronomy images collection which has grown fairly large and quite popular. Additional differences are to be found in the arrangement and descriptions of the material at Garbo. We have a unique directory structure which we have independently developed ourselves. Our file descriptions in our indexes also are somewhat different from the others, as you can see if you compare files that happen to overlap.
Quality control is a delicate issue, since there is no doubt that also the other sites do very well.
However, there have been a few cases when we have been even more demanding than the broad-scope sites before accepting material to our archives. To summarize, there are some features that underlie Garbo. Its scientific university background and its specializations. These make for the the biggest differences. There is no secret about Garbo's true purpose either.