There's several questions, all conflated here.
1) Are new Martin guitars worth the asking price?
2) Are there other NEW guitars offering a better tone for the money?
3) Is there anything out there as good as an old Martin?

to #1 and 2-- WHICH new Martin? They offer such a bewildering assortment of models that if what you "want" is to play something with a Martin label, you can get it, and it won't be (IMHO) as good a guitar as some others out there at the same price.

to #3: Again IMHO-- the Martins of 1920-1945 can't be beat. You can expect trouble every time you put a capo on and need to retune all six strings to get back in tune, but it's worth the effort if you're going to record with it. If you're doing a gig, it's probably a good idea to have a newer guitar which will have good intonation when capoed. I can think of several old time musicians (Tracy Schwarz, Kay Justice, others) who use a Taylor at gigs for just that reason.