I'm more of a fountain pen/mechanical and propelling pencil user, and the only ballpoint pen I have (other than the cheap freebies that sometimes arrive from here and there) is a Cross Century II chrome model. I use it mainly where a fountain pen just won't do, on things like plastic bank cards, some official forms, when gardening, doing machinery maintenance and so forth.
In a similar manner to that in which I spend some time finding the right fountain pen nib and ink combinations, it took me a while to decide which Cross refill was best suited to me. However, I'm one of those whose handwriting is a copperplate I finished learning around the time of the Manchester United Munich air disaster, and which isn't really suited to anything other than an ink pen. I do have some difficulty in reading things I've written with the Cross.
That said, I've seen some superb examples of handwriting made with ballpoints, which for me is a "How did he/she do that?" moment of admiration.