Everyones needs are different.
I rarely have a need for ISO over 800. For anything daylight or with strobes it's a hard camera to beat. I have plenty of of other bodies to work with but the 40d just feels right. For the booths it was a definite improvement over the T5's that were in there. Faster shutter, better live view and better IQ.
ASA25. Blast from the past. Agfapan 25 was my go to B&W back in the day. Magical stuff.