ideally good pp system should relate pp to ranking (u won't lose pp because u set a "better" play), so I actually love mania pp system before last change. in ctb you can lose pp due to overspin with worse accuracy or get higher combo with more misses. std is almost the same but you lose pp more easily. current taiko and mania system can still lose pp but mostly due to acc issue (mania is more painful cuz ratio exists and affects pp greatly), a little better than combo game imo.
overall I think: mania(score pp)>>taiko>=mania(acc pp)>>ctb>=std