I think it would be nice if you added some 'terrain details' to the first screenie and outside areas overal, it looks very unnatural to have a ground so flat, the tiniest elevation won't make a whole lot of difference for the gameplay and will in my opinion make it look alot better.
The average cs-er won't look at the ceiling for details indeed, but you're hopefully looking to not only please the average cs-er but also the type of play that's been playing for years and is bored of all the badly designed custon maps out there (since there's unimaginably vast numbers of them).
If you make a map with as much detai las you can possibly think of (don't cram it with crates or anything, but maybe stuff like vegetation, ceiling supports, decals, and stuff like that) that is realistic and doesn't make the maps gameplay / performance on poor machines suffer, you'll
please everyone that plays the map, and mos well made maps really attract more players than another de_dust or some kind of empty fy box.
I'd say you're about 90% done looking at it from this perspective.
But ofcourse, if the gameplay is good, people will play your map, it's just easier to get them to download and try it if it's eye-candy