Gman, we have one account shared with around twenty people for reviewing and we have about 8 folios in there in sizes from 8MB to 156MB.  I can tell you first hand that the orginal iPad does slow down the large the folio so we strive to keep things as small as possible.  Good luck.

Mike,

In our experience it's the hardware limitations of your device, not any limit set by Adobe, that will slow you down.  They recommend not putting articles adjacent to each other that have large amounts of interactive content.  I believe the viewer apps start caching the next article as soon as they've finished loading the current one so that everything is ready when you swipe to it.  For example, if you've got two articles with 50MB videos in each of them you don't want to put them right next to each other.  One way to keep your video size down if you're distributing to iPad is to create smaller video sizes (320x240, etc.) and play them inline instead of full screen.  Unfortunately you can't do this with Android currently.

Adobe has been very open with letting people use the Adobe Content Viewer to share and view folios.  They don't have any rules in place to limit you that I'm aware of.  Back in the days just after the beta they limited folio sharing to 1 folio per Adobe ID, but that limitation no longer exists.  You may want to look into paying for an Acrobat.com account if you're going to be hosting a number of large folios, they limit free accounts to 2GB.  You can bump that up to 15GB for $15/month.

https://www.acrobat.com/main/en/pricing.html

One thing a folio larger than 500MB will do is become more of a hassle to download, users may become frustrated.  The acrobat.com server is definitely slower than the Distribution Service so the large folios take even longer to download.  It also takes up lots of the limited amount of space on their mobile devices.

Andrew