planning to buy an Ipad Mini. browser upload/download supported?

I presently use a Nexus 7 (2nd gen). It's a great portable tablet, but its browser performance is not very stable. Some sites cause a ton of scrolling lag and sometimes Chrome crashes when streaming videos directly from websites. Surprisingly my old Lumia 800 has a more consistent performance in browsing.

That said, I plan on selling my N7 and getting the Retina iPad mini but also considering a Baytrail tablet.

Im not really an app guy. Aside from a few casual games, my tablet use has been largely confined to browser use. Heck, I even prefer the FB mobile site over its Android app counterpart. One thing I like about Android is the ability directly upload files (photos, docs, etc) to websites and download from them at will. I can live without a filesystem, but does iOs have a workaround to enable direct site upload and can you download docs, pdfs, etc directly? Also, does Safari on iOS 7 suffer the same crashes and lag in Chrome Android?