Tip! I read on the Frets website that when installing bass/wound strings, after winding the string, before tightening, take the string out from the bridge pin and twist it a few times, so that the windings are tight- this gives it a more brilliant bass. I just tried this and it makes a good, subtle difference. the bass strings seem to have more tension and are more responsive. Read the FRETS website for more.
I've been through a lot of string brands over the years, and yes I agree that MARTIN strings can take a while to break in, stay in tune and sound good.
I like D'Addario phosphor, or Elixer phosphor- never thought I'd like the coated strings, but to my ear they sound good, and I like the smooth feel.
For classical you have to try Hannabach! they are IMO so much better than the other brands- the strings sound great, and don't feel like "wet noodles" when they get a little old! they have a way of making the string so that is feels more substancial and the tone is more balenced between fundamental and overtone.