If it was mealy, it was probably improperly stored or grown in too warm weather. They aren't normally mealy. They're more tender and less crisp than Honeycrisp and have a pleasant texture.
I'm referring to whatever texture Macintosh usually have. It's not pleasant to me.
You're likely not getting good McIntosh apples in your area. The texture should be similar to a typical apple, but not as crisp as Honeycrisp. A slice of McIntosh should snap if you try to bend it.