My tip. Don't get too excited or worked up about TS. If a seat block sticks in a seat next to you, count yourself lucky. Never expect it. My hit rate is that about 1 in 5 stick. Perhaps it will make a difference when GGL becomes a separate tier, but at the moment the seat next to me is definitely not one of the last in the cabin to be allocated. I know that there could be many reasons for this (including other GGL pax selecting the seat), but my data sample is large enough to enable me to draw some broad conclusions as to how the system works.