I used to own a 2000 Pontiac Bonneville with the supercharged 3.8L. I dumped about $1500 in mods into it (stainless headers, high ratio rocker arms, high flow cat, smaller S/C pulley, high flow fuel pump, probably a couple other things I'm forgetting), and when I had it dyno tuned it made nearly 380lb-ft torque and 290 hp at the wheels. Small potatoes compared to modern forced induction engines, but made for quite the tire roaster and a heck of a fun FWD sedan back in the day. I was dumb to have ever sold it. If I ever find a gently used grandma owned L67 car (Park Ave Ultra, Regal GS, etc.) I'd be all over it.
IMO the Ford versions had the same potential (thought not sure they ever came with the Eaton M90 supercharger), but didn't have the volume and cheap aftermarket parts that the GM models had.