Having both the 60D and the Magic Lantern firmware - I can say it is AWESOME - though low light HDR video is crap, everything else is good. You will always be subjected to what hardware you're using and the limitations thereof. Here's a thread that most of the images I shot using the auto bracketing feature on Magic Lantern for me to blend:
http://www.ausphotography.net.au/for...8-Cape-to-Cape

In my opinion, worth it - especially for the lower end camera like ours! Seriously, I'm glad I put it on. The intervalvometer was the big seller for me! As for shooting in low light/high ISO - depends on what you're shooting, seeing as I'm predominately a landscaper I barely get over ISO200!