I like it, but it ruined a story I was writing. I was writing it on the old submit page, then I finish and click submit. It sends me to the new page without posting my story. I had to rewrite the whole thing.
Sta.sh is understandable, because it's essentially a second part of the site altogether. So the different colours serve as a good reminder what you're doing is your eyes only, but not the best on the regular site.
Its not too good on my eyes, but then it's probably just me hahah
I find the new one really frustrating sometimes, like when I'm typing something in the description box, there's that annoying white box with 'description' on it (the same white box when you hover over a picture with your mouse). Also the preview of the description doesn't show me the whole description. The button to add your drawings to your galleries is also something I can easily overlook.
But those are just small things and I'm used to it now