Hey pwmccarthy, it depends on the type. Typically, wood and moisture don't mix! Humidity and moisture can cause swelling, cupping, etc. of the boards. A type of hardwood that is better for bathrooms (and any area where moisture is higher) is engineered hardwood. Basically all that is different is the way it is manufactured. The structure makes it more resistant to the movement and changes that moisture causes. As for cost vs. trend, I think it just depends on your style. Would you like the look of hardwood in your bathroom? If so, go for it. If not, maybe tile is better for you. Hope this helps!