@Wintermonster, I think I mentioned some advice on the other thread about my polished concrete floor being beautiful, but easily scratched and liable to oil/grease stains (although I think it's my high shine finish that shows scratches more). Overall though the scratches aren't too bad as it's an industrial/rustic material anyway and the natural patterns in the concrete disguise them quite a bit (unlike with resin). Also, it will need to be re-sealed and polished in time so they won't last forever.
One downside to consider: it's also like sheet ice when wet so needs to be dry before any little ones go near it. That said, it's not a huge problem.
Have you got quotes from companies? I really do think they need an amazing sealant and so I'd be tempted to spend more to go with decent companies like Steyson or Lazenby. I've heard from a couple of architects (with experience) that don't really recommend them and it's mostly because of the staining issues.
My sister has a resin floor and I can definitely see how they'd get marked or scratched easily. And they're also very slippy even when dry! I can't resist sliding around like a kid when I visit. 
Also, can I highjack a bit and ask @Whattodowithaminute how careful you need to be with your floor re grease/oil stains, please? We do find that if we drop a small bit of cheese/pastry and it's not spotted until the next day then a stain will usually appear. We had a penetrating sealer applied (instead of a topical one) and I can never quite work out if the sealant isn't good enough or that's just the nature of concrete floors and you need to be vigilant? Part of me wonders if we should have just gone with large format concrete-look tiles, but then I guess I'd moan about having to clean grout and the floor wouldn't look half as beautiful! 