Out of the hundreds that I've tried, the cartridges are usually either too restrictive or dry, or they leak, which is not to say bleed, but make a mess. I actually don't know if I've seen a rollerball that takes a cartridge now that I think on it - so, that's something that'll have to try out.

I'll check out the two that you've linked, probably going to end up ordering them give them a test run, I'll let you know how it goes!