I started at 350 and that's still what I use most of the time. For light, non-technical articles, I can do 450, but it's a bit uncomfortable to focus that hard and I do miss things occasionally. I can usually tell if it was important or not though, so I know if I need to go pause and rewind. After playing with speedreeding off and on for a few years, I've come to the conclusion that it's definitely possible to read faster than I normally do with equal comprehension, but that there really is a limit and the claims you see from speedreading courses are hyperbolic. The thing I like about Squirt is that it eliminates the need to use a pacer.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.