Well, I'd like to take the time to point out that sector count really doesn't have much of a bearing on the level size, and honestly, neither does the BLOCKMAP.
Aerial Garden 2 is insanely detailed and breaks the 128K limit. However, the level has only 598 sectors. Nitric Citadel, however, a rather rushed map, has 602 sectors currently. I assure you, Aerial Garden 2 is MUCH bigger than Nitric Citadel. The reason is simple: Aerial Garden 2 is insanely optimized, and Nitric Citadel hasn't been optimized at all yet. Conservation of sectors and optimization make sector count pretty irrelevant at the end of the day.
For your question, JJames, I don't really mind if you use it all THAT much, but it is annoying to have to wait on many successive downloads. 15 seconds isn't an issue once. It's annoying when you're sifting through 20-30 entries and half of them use annoying hosts that make me wait to download the file.