I'm already on my third string change just for grins. It came w/ Martin MA540T Authentic, Martin's top of the line PB strings, they did sound great but stiff. Big bottom end. Must be the thick core.
I have a few sets of the old stand by, D'Addario EJ16,.. those were certainly easier to play and you could say more balanced, you could also say, lacks the bottom of the Martin Authentics. They're OK. Didn't have the sparkle and piano like sound of the Authentics.
Just slapped on a set of Martin MA540 FX "Tommy's Choice" Flex Core. I've liked this string on my 00-28, we'll see, they take a bit to settle in.
Curious to try some Monel string next. BTW, I've always just winged it changing strings on a slot head, I never had a system,.. recently ran across this video and man o' man, a great approach, makes immediate sense.