We just replaced carpet in our house with all three: red oak hardwood floors in the living & dinning room, bamboo in our family room and cork flooring in our master bathroom. And we put wool carpeting in our basement (love, love, love it!).
A few comments:
Yes, it is true you will see more dirt than if you had carpeting but wouldn't you rather see the dirt and be able to clean it than breath all of that dirt that lives (along with dust mites) in your carpet?
I love the bamboo! Looks great, easy to dust (sweep) and eco-friendly, if you get the right brand. NOT all bamboo is certified green.
I like the oak hardwoods. It matches the more traditional look and feel of the spaces but I do prefer the feel of the bamboo.
Indeed cork is not for everyone. Probably best not to do it unless you were into the house for the long run so that you get to enjoy your choice.
Feel free to email me if you have more questions. There are lots of choices out there and it took us almost 6 months to make ours!