Sorry, but I don't like the maps. I'm a longtime GM and I like to use such kind of maps but they have to be way more coool.
The texture is too repetitive and the symmetrical architecture is boring.
I can see no advantage in doing it in half an hour. Better do it in one or two hours and get some maps that really rocks.

Don't get me wrong. The maps you showed are a good starting point. There is nothing bad, but it's only the beginning for a nice map to play on.
There should be more different floor tiles, niches, pillars, interesting room shapes, dramatic lighting...