On SS/FG: simplicity, yes. low maintenance, yes. also, much lighter and more mechanically efficient than derailleur bikes with comparable frames. I commute on various derailleur bikes and a fixie on the same hilly route, and it makes no difference in commute time. They are undeniably a different and fun ride.

mbologna: if you want to get a good deal, go for the coda or bianchi during the sale. However, if you really liked the ride of the castro valley and the san jose, then here's an idea: go for the volpe. Since you already have a dinotte, the hub light is redundant (but you won't have to worry about batteries and it's not necessarily a bad thing). The volpe has a triple, as well as (short) semi-horizontal dropouts, so you could do a SS conversion pretty easily if you're still stoked on that. You get to have your cake and eat it too.

If you like the upright position, you could install cross levers on the drops and ride the tops. I think drops make the most sense for commuting, just because of versatility, and there are some like the noodle, midge, and WTB mountain road drop that are super comfy and have pretty wide tops. but that's just me.

I'm the guy who helped you out on your first visit, BTW, good to see you on BF, and thanks for the props! (also my apologies on the shifting issues--I try and do more than just a safety check--but sometimes bikes shift differently in the saddle than on the stand--just a wee turn of the limit screw was needed)