I can. I recently roasted up two batches of beans -- some El Salvadoran and some Costa Rican. I roasted both to a Full City (dark) roast level. They were very different. I finished the Costa Rican quickly. It was delicious. I'm struggling to finish the El Salvadoran. I'm terrible at describing flavors, but I'd say it's sour with a tea-like flavor.

There's a lot that goes into the flavor of coffee. The beans themselves of course. Brewing technique has a big influence as well. But also growing conditions (altitude, soil composition, rain/sun mix, etc.), processing (wet vs dry process, fermentation time, etc.), handling and shipping (dry or moist conditions), and probably more I don't know about.

I strongly prefer wet-processed beans (mostly south American varieties) over dry-processed beans (mostly African varieties are processed this way). I haven't tried honey-processed yet.

Green beans stay "fresh" for a really long time, but once roasted beans become stale quickly. I can taste the difference between my roasts a day or two after roasting vs days or weeks later.