I think this depends on load. Many times, seats are mass assigned just prior to 24 hour mark with no chance to change them as there are no other available seats until at gate. Knowing which basic seats are assigned at gate is a crapshoot if flight is full.

Seriously, what are the chances for a the worst/best outcome? Getting squeezed into a middle seat with two sweaty passengers next to you needing a seatbelt extender….a priceless experience, or best case scenario of two friendly people who become your newest BFF….. both a rarity but more likely people base their decision on a legroom space, baggage, window or aisle access. If saving $200 becomes a priority, forget the perceived negative inflight experience and focus on what you did with that $200 savings. After the flight, you have the world to spending that $200 savings.

Jiburi