It depends what you consider "lenient". CGC has always been lenient on production flaws and the nature of the 100 pagers is that the spine will almost never be "perfect". There will always seem to be some off-centering, small bindery tears, wavy spine, staple rubbing, poking through the cover...etc. CGC won't really knock it down for those types of wear. However, don't expect like some have learned that they will ignore creases, tears, or surface wear. Of the 4 9.8s that I currently own, I would imagine that only the Tarzan 235 CGC 9.8 would be universally accepted as being "worthy" of its grade regardless of one's personal preferences regarding QP...etc. It's in the CGC gallery so you can tell that it's a very nice copy.
Since I've probably submitted more of these books than any of the regular board members, I've gotten a good hang of what CGC looks for but I do get surprised at times. Luckily, it's to my benefit but I have taken my lumps such as the 7.0s and 8.0s that I got with my inital "larger" submission.
But...to be honest, other than one year when I got a bunch of nice horror 100 pagers from Terry's comics at SD, I haven't had much luck finding them at most conventions.