It really is simple, you'll never miss a post ever, and in fact it's
way better then the old forum as far as time involved if you just learn the new tricks.
Don't bother with the "read new posts" thing, log into the regular forum, if the kite icon is pointing at the forum heading (like website discussion) there have been new posts to that section of the forum so click in. Inside that section it's the same thing, if there are posts you haven't read the kite will be pointing at the threads with unread posts. Go read them, if you don't want to bother with some threads before clicking back out of that section click on "Mark all read" and it will clear those you didn't want to read. If you want to save a thread until later but there is a thread you don't care about you can open the unwanted thread(s) then click back, as long as you don't open a thread you want to save as new it will remain new.
It doesn't matter whether you've logged in 5 minutes ago or 3 weeks ago doing it this way. It doesn't matter if your coming in on 1 or 12 different computers, until you read the thread or click mark all read the forum will show you where any unread posts are lurking and take you directly to them.
That's the best part

right to the unread posts
In the thread title you'll see a little icon that says "New" if you click that icon it takes you directly to the first unread post to that thread so you don't have to re-read a whole thread looking for where you left off - This is way better then the old software where you had to start at page 1 or guess which page you left off at and read through 5 pages to see where you were last time.
It really is simple, and better IMO