The ionized interstellar medium (ISM) provides crucial insights into understanding baryon cycling within disk galaxies and tracing radiative and mechanical feedback from young massive stars. With new VLT/MUSE optical integral field spectroscopy, the PHANGS team now has a wealth of emission line maps that trace different ionization sources and physical conditions across nearby disk galaxies at the 50pc spatial scales needed to resolve individual HII regions. I will show my results from NGC 628, comparing the arm and interarm star formation, classifying the PN and SNR populations, and tracing variations in the star formation efficiency.