As promised, here are a couple pictures of the Calfee all built up and with a few hundred miles on it. We have decided to call it Tachycineta, after the lovely tree swallow's we have in our back yard,
Tachycineta bicolor, and because of the translation, Tachy = fast, cineta = moving. It seems appropriate.

The final weight came out to 25.2 pounds as you see it here, which I think is quite good for a $7000 total budget. The weight will eventually likely come down to 25.0lbs after a swap to a new set of captain's pedals (I just haven't decided on what to upgrade my whole fleet to at this point). I've been riding old style looks for about 15 years now, and have them on 4 bikes, so finally making the switch to something different is going to be costly (I only have one pair of shoes). I'm currently very tempted by the surprisingly light and affordable Time Xpresso 2 pedals (<$70, 220g), which would knock 150g off the current set, but I'm holding off till they go on sale and have more reviews on their reliability.
A few other notes that are worth mentioning: The bike rides incredibly! Coming from a 2000 steel Burley Paso Doble, the ride is really smooth and the handling incredibly crisp. It definitely feels significantly stiffer while accelerating and climbing, yet smoother over rough roads and bumps. It climbs wonderfully, and you can definitely feel that it is light when the roads turn uphill. To be honest, the ride is probably more similar to my single road bike than to the old tandem. The positioning for the stoker is a huge improvement over the unfortunately short cockpit of the Burley, and the captain's position feels almost perfect, if a bit less aggressive than I would usually opt for due to the frame's 2cm headtube extension. That being said, I don't mind the slightly more upright position for a tandem, and with the shallow drop bars, I am able to spend a lot more time in the drops rather than on the hoods which puts me slightly lower than my road bike positioning on the hoods.
As for specific parts: I am extremely happy I went with the compact double SRAM setup. The shifting is superb, and I honestly can't tell any difference in shifting performance between this bike and my road bike. It is nice to have a familiar shifting setup and the more comfortable hoods of the SRAM, as my hands and Shimano shifters just don't fit well. The gearing (12/30 with 34/50) so far is perfect for our usual terrain and riding style. We live in an area with lots of rolling hills and no climb longer than a mile or so. We've spent most of the time in the 50T chainring except for climbs that bring our speed below about 15. Below that, we can comfortable spin the 34T down to about 8mph. We haven't spun out the bike because none of the downhill's around here are really long enough, and if we did get above 35mph, we'd just coast anyway.
The captain's saddle (cheap full carbon 100g from ebay) is definitely firm... but surprisingly comfortable so far. I've always been pretty flexible about saddle choice, and at least for me with a pair of good shorts, I don't get any discomfort from the hard carbon. You can definitely feel it supporting you, and you can also feel if you sit down wrong or shift to a bad position on soft tissue. The stoker likes her saddle (
Selle Italia SLR Lady Flow) more than any other she has tried. It too is firm and supportive, but the extremely large cutout really works for her, and it is impressively light (185g). The shockingly light/cheap Loaded USA headset (66g, $47) works like any other headset. If it lasts a few years, it will be worth it.
On the oddities notes: The cranks are intentionally 2T out of phase (captain leading). We both have ongoing knee pain issues, so we are trying this out to see if it helps even out our pedal stroke while still allowing us to climb out of the saddle comfortably. So far it has worked great.
Overall, we are really happy with the bike. It was a fun build process, and it was nice to see that with a lot of patience looking for the perfect used frame, and buying just the right items on sale, we were able to put together our dream bike within a "reasonable" budget. Thank you to everyone who offered suggestions and thanks especially to Twocicle for deciding that they just had to have a Calfee with couplers only a year after first acquiring this frame.