You are correct in what you heard. Marble is a porous stone and even sealed only gives you a few more seconds/minutes to wipe up a potentially dangerous spill: i.e. oil, vinegar, wine. If you are a conscientious cook then you should be OK, but if you tend to be more lax I'd avoid marble and use granite instead. You see it ALL the time in pictures and it looks gorgeous but you can see my hesitation to recommend it for kitchen use. consider this instead as well: Super White granite. It's very similar but not a marble.