A swaged pellet will be more uniform and easier than cast but, it will also be softer than cast lead. Given the equipment I think I'd opt to swage and avoid lead fumes and fuel use melting lead in the first place.
Why is a swaged pellet softer? I find freshly cast lead softer than stuff that's been sitting around for a few months. I also gather if you correctly melt lead (i.e. don't heat it too much) it shouldn't give off fumes (although don't hold me to anything!).
The cast mould looks appealing as it's more 'self sufficient'. I wonder how the pellets would perform in my air rifle compared to the ones it seems to favour?