1200 miles? Zactly the reason I don't use nice tires on my bike. I've tried but get about 2000 tops out of race tires. That would be 2 to 3 tires a year. Can't afford it year after year (13 consecutive riding).
I use a Specialized Armadillo 700X25 on my training roadie. It feel s heavy at first but last forever. I'll train with it, climb and whatever then place a GP4000 for an event day . That's it then take it off.
I save the good stuff for Gina's roadie as she will get about 5000 out of a GP4000.
Aramdillos is the longest lasting I've found. I've had terrible luck with Gatorskins, single and tandem. We got about 1000 miles on the Gator and the chord is showing through!
Maybe it the combined weight on the tandem but $40 a tire is an expensive lesson.
I did find the Serface Seca at REI after reading the tandem forum. Folding version is at the LBS for $35. I found the wire version for $20 at REI. 700X28 worked nicely on the tandem. Rolled well but durability will tell in time.
I did see the 700X25 also $20 but didn't see any 23's. Heck, I'll use a 25 on my roadie, for training.
I think there is a thread in the road forum on Serfas today!