Here it is today. The ovo configuration changes quite regularly, I need more tubes and bits so that I have it how I really want it - so frustrating being limited by what I have!
I wouldn't keep reading unless you're a total cage nerd!:
I've tried all sorts of shelves in the past and have finally cracked it - bathroom sucker accessories from ikea which screw to tighten up. I have a towel rail across the back and two soap dishes on the sides to support a plastic shelf.
I tried to move one of them earlier and I had a REALLY hard time getting it off so there's no way they'd come off by accident. I don't have to faff around cleaning around legs, the shelf is really solid, and there's nothing to soak up pee.
They tend to pee on anything with enclosed areas so lots of my lovely wooden things have had to go in the bin
Instead I now have grass nests, small cardboard boxes and plastic dens. That way anything that gets peed on can be cleaned or thrown away.
To keep some of the natural feel in the cage I've bought "open" wooden accessories - ladders, steps of all sizes, climbing frames and the large twisty branch which was expensive but totally worth it - the mice love it and it's so handy to take them up to the levels.
The ovo has been a brilliant addition - they love all the tubes and different areas. I use one of the pods as a food dish which keeps the mess in one place and is easy to clean. They have a tendency to sit in the bowl and dig all the food out otherwise (although I found some great bowls that nearly solve that problem if anyone's interested).
It's made cleaning out less stressful for them as well since I can heard them all in to the ovo before I clean the cage and vice versa.