777 will, over time, develop a 'crud' ring in the chamber that takes a bit of effort to remove. And it's sensitive to compression - sensitive in that it is inconsistent if over compressed. It also smokes less, which is a personal issue - some people like that and some don't. It's significantly more expensive most places. Pluses are that it's hotter, cleans 'easier' (I don't really agree with that, but it's the popular line) and takes less powder to get a given result, although that's really just another way of saying it's hotter.
So, 'better'? No, just different.