Are shallow-mount subwoofers worth it?

Verified-purchase reviewers and r/CarAV regulars consistently say shallow-mount subs like the Pioneer TS-A2500LS4 and DS18 PSW12.4D are a real compromise: they fit under seats or behind truck rear seats where a normal sub physically cannot go, but lower xmax and sensitivity mean they won't match a comparably-priced standard sub in a proper ported box. Buy them when space dictates, not when you have a trunk to spare.