IMHO, Anything past medium might as well be beef jerky. Of course, if you have a really intensely fatty piece of meat the fat could offset the fact that the meat is dry like the sahara. My personal preference is medium rare, especially with a lean cut like a tenderloin. The flavor of the juice is great and you don't get that flavor once the juice is all cooked out.
2 - 22.5" WSM , Weber 22.5 Performer and a very tolerant, very Beautiful Wife!!
Black & Blue Thermapens!!
KCBS CBJ & TC #55078