was it because of dl size or the look of fs1 content
Download size. A not-insignificant number of people still had 56k modems during HLP's early history. That's why you'll occasionally see "56k users beware" on old threads, especially image-heavy threads.
The download experience these days is leagues better than it was back then. Back when we were hosted by 3D Action Planet (pre-2006), all public downloads were required to be hosted by FilePlanet. You would have to wait 2 or 3 minutes to be "added to the download queue", and then once you were at the front of the line you would have to wait another 10 minutes or more for the download to complete. (The ST:R trailer gives a wink and a nod to this with "Not Distributed by FilePlanet" in the fine print.)