I've never hunted the tag, but I did fly thousands of miles over the KP this summer and can confidently say that there are not a ton of bou there. I'm sure someone knows of pockets where they may hang out, but I never saw more than two or three animals at a time and looked over a lot of that place. Would be a cool tag for sure but I wouldn't imagine it'd be a "gimme"
All of the other herds in southcentral are apparently in pretty rough shape. Rainy Pass herd barely exists. Nelchina is a shadow of its former self. There are a few animals around Denali, but all the dudes who know way more about it than me said that should really be viewed as an incidental more than anything.
If you want "Caribou" and "success rate" in the same sentence, everyone I've heard says go north and find a good transporter.