I haven't seen anything that would change my original recommendation. I have a Sigma 70-300. I go out and shoot with it every now and then, but it doesn't produce images like the 55-300, which doesn't produce results like the DA*60-250 or DA* 300. I consider the 55-300 to be good enough in the long end that regardless of what you get, you'll still like those images. The Sigma is really good from 100-200 but the long end is only good up close and in macro it's just soft. I'd seriously suggest , it's not a lens you want to keep if you're trimming things down.
That said, I still have mine and I still haul it out every now and then.
Sigma 70-300
Sitting in the same blind with the same tripod a few days later. DA*60-240 with 1.4 TC
From what i've seen the 55-300 would have done a lot better. Sure you can mess around to see what you want to shot, but some of the keepers you get with it are not going to be keepers anymore after you get a better lens.
It is noticeable at screen size.