Positives: ChazDesigns is one of the best Sim-makers around, only topped by Jirka (in my humble opinion). Naturally, he'd be one of the first with a realistic celebrity Sim.
Negatives: SKIN REPLACES DEFAULT!!! While this Sim looks great, every other Sim will have the same features if you download her. I'm still waiting for these titans of skin tinkering to use makeup masks for their celebriSims, so you don't have to have a full skin set to have celebrities.