ALL of the 319s and 320s I've flown have 12 FC seats. Very nice in FC on the op-up I got one time on SAL-IAH.
Exit seats are very good in coach, free alcohol in coach. Good service. Agree bulkhead could be a little tight (that would be seat 4 on all aircraft).
And yes, I've seen them substitute AC between 319 and 320.
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