Similar experience to sibling: a disinterested human isn't going to ask for 30 different detailed things to add to, or change in, the paper that could technically be improved but aren't worth the additional page real estate. An LLM reviewer definitely does this.

There is still a difference. Previously, if the review was low quality and superficial, it was also quite short and easy to answer. Now I receive fully LLM-written reviews of 2-3 pages (or more) of superficial comments asking for tons of additional text and experiments that are almost always outside the scope of the work. Answering such a review requires a lot of work with absolutely no gain.