deadsea - 4:49 pm on Oct 23, 2012 (gmt 0)
The fact that 'time spend downloading page' has gone up is worring to me. The redirects you put in place should be very quick to crawl compared to entire pages that your site needs to render. With the situation that you describe, I would expect Googlebot to be doing a lot more crawling and doing most of it quickly.
I suspect that your site is experiencing some performance problem that could be contributing. How does your site perform for visitors right now? (WMT -> Labs -> Site Performance might be able to give you some idea).