When you look at a thread not accessed directly via the Forums option, you can't tell what forum a thread belongs to. Eg posters often don't specify the airline or hotel in question because they're obviously posting within a specific airline/hotel forum. When I see that post via iPhone, I often have no way of knowing they're referencing (eg) United.

Next, you can't see the entire thread title if it's long.

Last, the home page isn't sorted chronologically. It's sort of chronological, but with a mix of random.