3* maps would only be boring if you've never taken the time to actually play them and/or have only ever watched high-level play and/or only play 4*+ for...some reason as a newbie.
Are they the most difficult maps out there? No, I don't claim that (for the most part). But I personally just feel like people don't really give them a fair shake in that regard.
As for OP, Happy Satoko had a pretty good line. If you think replaying for better scores will be fun/helpful, do that. If you think it won't, don't. I would argue it almost objectively is better depending on the map or map type, but that doesn't mean it will always do the individual any good (i.e. you're already good at that particular kind of map).