Boscovian always seemed ok, but nothing special. Maybe I've underrated the game. That said, what part are you dying at over and over? I was stuck on the second base for a while until finally beating it and the next 3, before getting stuck again on 6.
You should give yourself the max amount of lives possible to practice as much as you can in the later stages. That's always my plan for improving at arcade games. After a few weeks you don't need the extra lives and it's back to business as usual. I even have different "initials" that I use for any such "cheated" scores, since MAME tracks all that (XXX, WIZ, or ZOD for scores gotten with extra lives).