Seems like this type of thread is initiated once or twice a year.
I found the Specialized All Condition Armadillo to be excellent at 27".
Yes, the Armadillos are well made, tough and flat-resistant.
Slightly narrower than the 27" Gatorskins I've used, but more resistant to cuts from any angle and of course with a stiffer casing.
So many more choices with 700c, such that I can find more of the exact style of tire I want and usually at a better price, basic tires excepted.
I actually do about half of my riding on 700c discards, usually un-worn front tires or new-looking rear tires with a small, boot-able hole in the tread region. At the pressures I run (I weigh 145), such booted tires are still entirely reliable.