I threw on around 500 books. Love my K3, but can def see where people mention slowdowns with too much stuff on there. The processor/UI is just not up to snuff for mass loading of content IMO. And just for fun I threw on like 100 favorite mp3 tracks but the experimental player is a major FAIL so they are just taking up space [and have not had time to look into alternate music player software for K3 yet].
4GB for ebooks is pretty ginormous IMO - I would hope for a vastly improved UI and processor for the next Kindle version.
OT, but I personally would go in a heartbeat for a new Kindle with:
- sexy metal frame and buttons
- no keyboard [replace with on-demand soft-screen keyboard but keep similar form factor]
- faster processor [which would go a long way towards making the UI snappier]
- uSDHC support
- halfway decent audio chipset and usable software player logic/GUI
