Originally Posted by saveri

Seat selection for Silver/Ruby or anyone else is complimentary at check in.
It is correct that if you pay for a seat in advance and there is a re-assignment due to an equipment swap you might not be able to select a new seat yourself. In which case use twitter or call QR and they will assign you the seat you want since you have already paid for it.
On four flights while Silver I found that I was able to select seats free of charge 96 or 72 hours (can't recall which) before the actual flight time (not a published benefit). This was not applicable for preferred seats which continued to be paid options.