Dedoimedo posted a review on Ubuntu 13.04
Almost with regret and personal shame, I present you the worst software review ever. This is an extremely highly negative review of Ubuntu 13.04 Raring Ringtail, with Unity desktop, tested on a laptop with Nvidia graphics card and Broadcom Wireless, covering installation, drivers setup and a short, painful experience, with myriad problems like kernel crashes, Nouveau driver excessive memory and CPU usage, very slow network speed, unbootable desktop after network restart, inconsistent behavior, worrying trends, dashed hopes, and more. You know what, don't even bother to read, it will sour your day. It sure did sour mine.Ubuntu 13.04 on me high-end box - Horrible