As you may know, I'm a Navy officer; I was stationed in Sigonella (which is a US airbase in Sicily) for 3 months in fall 1997, working with an air squadron doing Bosnia overflights from there.
The island is beautiful and historic, whether your preference is Roman, Norman, Templar, whatever. Budget to bring home some of the wonderful pottery; several towns there each have their own special motifs. The food was simple but good; there is a little town (named Motto? Motti? It's been a while) a stones' throw from the base that has several good restaurants, a weekly market, and good gelato & bread. Many base folks rented housing there rather than Taormina, which is altogether too close to active Etna. The drivers weren't nearly as crazy as in mainland Italy; the roads are pretty good over most of the island.
Bottom line: Sigonella is a classic small town, with all that that entails. Will you be affiliated with the US Military, and thus have comissary/exchange privileges? Life will be far more expensive and far less varied there without that.