OK, this new design is clearly ridiculous. While there was always some overlap between duplicated links in the black bar and further down the page in the sidebar, having the two links sets separated like that allowed you to navigate from different areas of the page - and to choose which area was best and most comfortable for you. Plus the advanced search tools were in the less visible spot (the sidebar), which made sense from most user's perspectives - as in, don't crowd the most visible areas with too much visual clutter.
But now! Now you've got two sets of mostly duplicate links an inch apart from each other up top. And to get to the advanced search tools you now have to click the Search Tools button, then wait for the JS to lower another bar that works exactly like a dropdown, then click the tool you need, then mouse down and select the exact search tool you want. Four steps! Four. 4. And to get rid of that secondary dropdown bar, you have to click the Search tools button again. And you'll want to get rid of it when you're done using your advanced tool of choice, otherwise it will annoy the crap out of you laying on top of the search results as it does now.
But of all pages to take this functionality away on altogether, you chose...Image results! The one damn page where you constantly need to refine results by date, size, color, file type, and so on; it is indeed an inexplicable "design" choice to make since it kills usability on those pages altogether.
For those saying Google did this just to make room for more ads, every
Google design change does exactly that, but this one is even worse in that regard; if you visit this page: https://www.google.com/search?num=10&hl=en&site=imghp&tbm=isch&source=hp&biw=1008&bih=560&q=buy+ipad&oq=buy+ipad
with your adblockers turned off, you will see iPad ads now take up the full length of the page across the top. Without any sidebar in the way, Google can use the full width of the page - any page, not just the Image results pages - to run as many ads above the fold as they want. They are only limited by your max screen resolution, but they can always just add scrollbars to work around that problem.
As any of you more tech-inclined folks have probably noticed, the CSS for #leftnav
remains intact within Google's source - but rather than use "display:none" Google is just generating the new topbar and hiding the old sidebar on the fly, page by page, using plain old JS. All of which leads me to conclude that there's no reason Google can't offer an option to toggle the sidebar ON, since there's still room for it where it was originally, and to toggle the sidebar replacement up top OFF. It's not like Google will need to re-create the original code for the sidebar - it's still there and still in use in many instances (and in most other countries, as of this writing).
I don't like the idea of a design change this massive that decreases usability as much as described above being forced down all user's throats with no option to toggle any part of it, old or new, on or off as desired, nor do I think it should have to fall to the userscript and add-on authors such as myself to have to code things back to the way they were, when the way they were was vastly superior to the way they are now.
Also, make sure you're registering your complaints about the missing sidebar and other missing functionality in this thread: http://productforums.google.com/forum/#!category-topic/websearch/xcv50_kJ9Pc