I too enjoy the mandolin cafe and highly recommend it.

The first time I tried mandolin, while in high school, I had the mistaken belief that it would be easier to tune it like the highest four strings of a guitar, ie DGBE. Dumb. It works but not near as well as in fifths. Properly tuned in fifths the notes just flow under the fingers. I abandoned it until about 15 years ago and have since been playing it as much as guitar.

I'm currently waiting for the delivery of a custom made mandocello-ish guitar. 25" scale, 4 pairs of unison strings, guitar shaped body, and I hope it will fill the gap between guitar and mandolin for me.

To answer your question though, I find playing both improves both, like others here.

Peace and picking, Mooh.