The Flying Cloud of any size is really no smaller than a GT or Serenity of the same size. It's just the details that are different. (That said, I REALLY wanted the Serenity colors! It's entirely possible that those lighter walls would make it feel bigger. Also, the cupboards over the galley are a bit smaller on the FC because of the airplane style doors, but that didn't matter to me so much.)
We chose the front twin because it felt bigger with the longer "hallway." Also, the access to the underbed storage from the outside was a big plus. We tend to have more outside stuff than inside stuff.
Although I've had a convection oven before and liked it, we went with the regular oven because we boondock and I'd rather just use the propane oven. But I still go back and forth on this decision...maybe I'd rather have the space and just not cook...?
And just a plug for the Albuquerque Airstream dealer...they've been great to work with so far; responsive and helpful.