Arcadia from Master Special 03 looks like it's pretty loud, but it's not completely maxed out. That's one song where I wish I could hear more of the different instruments (Arcadia is one of my favorites right now), but that problem may not be due to the dynamic range compression. I looked at Hibiki's and Yukiho's Overmaster tracks from the Master Special series and, except for the beginning, there's no dynamic range. However, those two Overmaster tracks sound fine to me too. I guess the consistently loud dynamic of Flower Girl and Overmaster suits those songs. The rest of the songs I looked at appear to be pretty good: they've got a decent amount of dynamic range.
I watched a music video of Shinku on YouTube and you're probably right. Except for the voice of the singer, the music is almost exactly the same.