I think youre doing a wonderful job dwsel! its looking great! A few minor things are keeping it from photorealism - I think the walls have a lot to do with it, the tiles look very flat and textured, they could benefit from some depth & a bit of reflections.
Also , basically , the rest could use a tad bit more reflective surfaces, the sink/toilet , the shower cabin, the door could use some glossy reflections, - bathrooms are reflective places 
The composition could also use a tad bit more attention , a lot of the items are only half in the image & there is no center piece, maybe even adjusting the aspect ratio of the image might work.
The lighting is looking very good! I like the shadows & the subtle GI is great.
Keep up the great work & ill be looking forward to where it is heading 
Thank you for in-depth comment.
I can see some problems you've described.
About reflections:
Almost every material (except for the green plastic of the cup) uses reflections, about 80% of them are glossy. I started with higher levels of reflections specular, but it happened for me too look too shinny so I settled with the most of the materials at Kr, Ks ~ 0.05-0.15. I agree now that I could push reflections a bit higher for sink and toilet
Tiles on the wall come from rather matte collection with additional shiny motif:
http://www.cersanit.com.pl/katalog.php?mod=seria&id=25&dzial1=25&nr_dz_gl=5&lang=pl The biggest pain sits in the materials limitations of An8 scanline and ART. Usually mortar between tiles has different material (without specular and reflections), and the geometry displace is used instead of simply bumpmap. I wasn't sure how to do this in Anim8tor, still I didn't want to model each tile separately being afraid of 'too detached look'.
Next pain I have is with the cabin transparency. As you can see the window is totally behind the cabin. If I left it on the final render I wouldn't have light at all at the final image as ART does not respect visibility and transparency settings. Instead final 'skylight' image is combined out of three renderings (see attachments for simple explanation of how plexi appeared on the final version of 'skylight' pass) and 'ambient' render does not contain plexi surfaces at all to keep constant and flat lighting! When I started compositing reflections for plexi I've decided for glossy look because reflections could be of either fully lit bathroom or almost black, totally shadowed environment. Sharp reflections would look much less natural and would take 4 times more to render (because I render reflections passes at half resolution) but glossy reflections give at the same time subtle SSS look.
I'd appreciate any tips how to overcome these limits...
About composition:
I'm doing this visualization after the simple vis from one of the 'plan your house/flat' programs. The person who was doing the first simple look decided not to enter this bathroom. I guess that because of lack of space camera angle and deformation of the image was unacceptable. I've decided to fix it though in the postprocessing. Currently camera is placed at longer wall, at height of 1,6 meters, tilted by 10* downwards. This was the only way to collect all the most important stuff in one view. Look from the opened doors wasn't really interesting. At the back of the current view you have only not interesting heater
I'm wondering what I could crop more from this view - I'd rather love to expand it even more
I was even thinking about adding spherical, 100% reflective ball and place camera on it to have fisheye look. Again I'd have an unavoidable problem with casting shadows by this sphere so I dropped this idea, even when I bet it would have a really good look...
If you have an idea for interesting look feel free to crop and overpaint the last rendering.
I have 3 renders ( 3*3 = 9
) to go. Next sunlight/moonlight is planned: strong directional light with rather hard shadow, secondary beam(s) reflected from the floor/wall/objects and diffused at the place of hit. This will finish 'day look' and start making 'night look'.
