Ditto what Dianolo said. I think that would look pretty terrible. Your contractor's right that new wood can't exactly match old wood, but it can do a heck of a lot better job than porcelain tile can. Choose the same wood species as what's in your house already, use unfinished flooring so you can refinish all the floors at once, and it should look great. (If you choose prefinished wood it will never ever match--to make it look right you will have to refinish all three floors, i.e. finish the kitchen floor and refinish the other two, at the same time using the same stain and topcoat.) The other problem with porcelain tile, regardless of what it looks like, is that it's very hard on your back. It's surprising what a difference the flooring surface makes to your comfort--you wouldn't think there would be that much difference between a hard surface (wood) and a super-hard one (porcelain or stone tile), but there really is. People with tile kitchen floors generally end up buying gel-filled mats to stand on while they prep, cook and clean up. So basically I would recommend either using wood and refinishing all the floors so you get the best match possible, or using linoleum or vinyl in a color/pattern that contrasts with the wood instead of trying and failing to look like wood. If you feel absolutely compelled to use porcelain tile, get a style that contrasts with the wood (and get ready to buy some gel mats and leave them laying around your kitchen).

If you are changing exterior walls, it will change the exterior and then an architect is the right way to go so you end up with a pleasing result and not just a "remuddle" as others call it here. If, however, you are redesigning the kitchen (only), then go with an independent kitchen designer. Not one of those cabinet co designers that only sell their own product. Someone that actually designs the kitchen for your needs and can work with contractors. Someone with one of the accepted KD designations: http://www.hgtv.com/remodel/kitchen-remodel/understanding-designer-certifications Hiring the contractor without having the kitchen designed in detail with specifications will get you in big money trouble on a major design feature. Builders build. But they need the specs and plans before they can bid appropriately, otherwise you end up with inadequate allowances and cost over runs.

Solid hardwood that you can refinish again and again and again for 60-100 years. Or you choose the product that comes the CLOSEST to your "ideal floor" and then live with the down-side of that choice. Many homeowners expect "indestructible" from materials that are easily marred. They are still perfectly functional. They just look less than ideal. It all comes down to homeowner expectations. And the concept of "wants vs. needs". I've seen clients expect indestructible, life-proof flooring (ie. what you would get with a stone floor) from cork flooring (the softest wood in the world of flooring). The cork was still doing it's job but the homeowner didn't like how it was behaving. In fact the cork was behaving like cork - no better no worse. But the homeowner's expectation was a floor that would be live like stone but feel like carpet. Totally unrealistic expectations for cork. That being said, the homeowner needs to figure out NEEDS (kitchens and baths NEED water proof flooring) versus wants (wanting a floor that is soft as carpet but water proof as well). There is no 'perfect' floor that gives everything to everyone. Figure out the NEEDS the floor must have (characteristics) and the figure out which categories of materials will GIVE YOU those needs. And then make the best of the options you have been given.

" I would attack’s it with a sponge at least to see if you can clean that up." You do that and you own the entire thing, make him clean it up better. Sooner the better as grout hardens over time. Also as alluded to above he needs to remove the grout at all chnages of plane and use 100% silicone caulk.