Mattmiller,
I am curious which 45 RPMs you have heard.
I have found that the 45 RPM LPs that I have bought are sonically well worth the cost and inconvenience of flipping them more frequently.
Some standout 45 RPM LPs I have bought: new MoFi Bob Dylans, Mingus Black Saint & Sinner Lady and Ah Um, Coltrane A Love Supreme, Dolphy Out to Lunch.
Now, will 45 RPM sound much better if the original recording or mastering isn't very high quality? Likely not.
But for music I love and cherish (and know to be recorded well), I find 45 RPMs well worth while.