What is the most annoying part of opening Apple iWork files without a Mac?

I built iWorkViewer because I kept receiving Apple Pages, Numbers, and Keynote files while working on non-Apple devices.

The problem feels small until it blocks you: you are on Windows, Android, Linux, or a shared computer, and someone sends a .pages, .numbers, or .key file. You do not want a heavy document workflow. You just want to open the file and read it.

iWorkViewer is my attempt to make that first step lighter: open Apple iWork files in the browser, with no install and no signup.

I would love feedback before launch day:

1. Which iWork file type is most painful for you: Pages, Numbers, or Keynote?

2. Do you care more about preview quality or export options?

3. What would make this useful enough to bookmark?