I have a few.
First, LL sites that don't understand the content. I have made non-nude/tease types of sites and been rejected for not showing enough nudity. Teasing and not showing nudity the point of the whole site. I have also made voyeur and amateur sites where to quality of the pics/movies wasn't top notch and have gotten rejected for low quality content. The point of many voyeur and amateur sites is that they are supposed to be lower quality to reflect the real/taboo nature of the niche.
Second, like someone else said, the 24 hour rule. I understand it it fully, LL's don't want to get flooded, but what ends up happening is that on Monday I start my submissions at 1pm, I have to wait until 2pm on tues then 3pm on wed and by Friday or Saturday it is 5 or 6pm when I'm submitting and at that hour I should be drinking beer somewhere
. 22 or 23 hours would let me start my submits at 1pm and finish them by 2pm then I could do them at the same time the next day.
Those are my only real complaints. Otherwise I am cool.