Grout is either plain Portland cement or Portlant cement + sand. (Yes, I know there are epoxy grouts, never tried it, don't want to). Both are porous, sealer mitigates that. However, sealer may not last forever; is that a big deal? Certainly not if the tile is going on a slab, probably not if on a wood subfloor. It can always be resealed.
Nothing is easier to clean up than a tile floor unless it is a tile floor with light colored grout. IMO, IME, YMMV. __________________
The dish could break, the tile could chip. ___________________
The thing that kills feet is surface that is both hard AND flat. If a floor is hard but less than flat it is much easier on feet. For example, I tiled our hole house with Saltillo tile which is very irregular on the surface. That irregularity means the pressure points on your feet are constantly changing as you walk or even move slightly. Now, that irregularity is not matched by any other tile I know of but some have a lesser irregularity. ____________________
Comments Some have suggested using large tiles to minimize grout area. One could use relatively wide joints too. Small tiles are easier to lay because they can follow an irregular laying surface; bigger tiles - 16"+ - need a better surface, more attention to spreading thinset evenly.
Some strongly favor porcelain tiles vs ceramic. There are two primary differences...porcelain is color through (chips less apparent) and denser, said density resulting in less water absorption which is why they are recommended for wet areas (I don't consider a kitchen to be a "wet area). They are not necessarily more slip resistant than glazed tiles as any tile can be made slip resistant, all will have a coefficient of friction available both when wet and when dry.
The down side of porcelain is that it is harder to cut (also pricier).. Use a diamond wet saw? That will certainly cut it but every cut edge will have chips (same for ceramic). I much prefer score and snap as it leaves a clean edge and is faster; true, the edge will be sharp and will need to be honed a bit but less so than needed to hone out chips.
More on ceramic vs porcelain... http://homerenovations.about.com/od/tiling/tp/4-Ways-To-Pay-Less-For-Tile-Online.htm