Martin guitars have set a high standard for such a long time that there are plenty of excellent older instruments to hear and play. There are plenty of other good guitars. Many of them are better one-on-one than some Martins. Nevertheless a century and a half on top of the heap earns a instument maker a lot of respect.

There isn't any maker of guitars that has a larger number of excellent guitars out there in the hands of serious players.

They sound great. They are solid and durable. They have a great reputation. Everyone who buys one makes money as it ages and gains value.

They cost too much for what you get, but I still have yet to meet someone who bought a Martin and regretted their decision later.