Levin's 90s premise - that a disturbed, Peeping Tom millionaire landlord has rigged up his entire Manhattan building with hidden camera equipment so he can spy on his tenants' most private moments - now seems unbearably quaint in the age of reality TV, surveillance cams on every corner, cell phones and cookies. These days, the landlord could have called his experiment Big Brother and charged Kardashian wanna-be's high rents to live there. No need to knock off the people who began to figure out his set up!
Levin is also a playwright, so his books tend to have a lot of "stage direction." People crossing rooms, sitting on chairs, picking up phones, sitting down again, crossing a room again. Sometimes, in the case of Rosemary's Baby, the underlying threat is so horrific that these mundane stage directions add a twisted normalcy to the suspense. In other cases, it's just irritating. Sliver is somewhere in the middle. Mr. Levin also has a tendency to use pronouns for long periods instead of character names, ostensibly to leave the reader guessing who is doing what, but that can also leave the reader completely bewildered as to who is doing what, and that is especially glaring in the first quarter of this book.
That said, I still think his suspense novels are better than the vast majority of the ones published today, and he writes women better than most female thriller authors write women. In Sliver, for instance, the protagonist is a 40-year-old career woman who apparently has zero desire to get married or have children, and yet is constantly being described as sexually desirable by the male characters. Try to find that in a book of any genre today.
I also give Levin points for having a cat save the day.