Personal preference - they both look great! But the black grout is more of a statement (which i love!)

Jeff Leake - they are used for different purposes, one is to seal awkward gaps and the other is a overall put it on and leave. Silicone is messier and more expensive and to use it the way you suggested would most likely take four times as long to place not including clean up. This in turn bumps the bill up four times. This along with other reasons i.e discolouration, cleaning, longevity, ease of use the cost of silicon vs grout, masking tape is why tilers don't do it this way. The more time they spend on one job means the less jobs they can do in a week which loses profits. Add on to this with the more costs involved upfront for a tiler versus what the client pays (sometimes clients hold out on payment) means they go into debt and cant pay there suppliers and workers. Hopefully this answers your question. Macy-jean - Builders know a bit more than you might think and because a product says it does something does not mean it actually does it well or better than something else. They also know if it can be best used somewhere else with a better result. They always take time if something can cut down on time and money and can outlast another product in durability. 7 year warranty on builds means the less time they have to go back and fix something the more they save. Believe me they are always looking for something that cuts down on costs and time. They are also approached by different companies willing to give out freebies or competitive prices to try there product too and encouraged to endorse and switch other tradies to them also. This could be a longer conversation as there is more that goes into it but the short of it is Time and Costs.

What grout have they used? I thought there's a newer grout doesn't need sealing, what's it called, epoxy grout? Also check what they used where the vertical meets the horizontal as it's supposed to be a flexible product but builders don't always take the time to do that correctly, by the time the tiles start cracking they'll be long gone.

Thanks Bigreader, we did not realise that standard grey was not the actual colour we chose until I mentioned to our site supervisor that it was wrong. I feel conned by their process of letting me choose something specific and then making it vague so they have the opportunity to suit themselves without worrying about having to fix it. I agree the grout sealer might be the best option. Do coloured grout sealers work?