I own one of them (
https://www.smith-wesson.com/firearms/model-642-0), although it's currently back at the factory having fit and finish issues corrected. More on that at the bottom.
I paid $450 for mine, which got me a revolver that has no lock, a better than usual boot-style grip, a chromed trigger and thumbpiece, a cylinder that was cut for moon clips, and what appeared to be an excellent factory trigger job.
To elaborate on the last point, I had a friend who owned a ~10 year old regularly shot 442 accompany me when I went to pick up my gun. My gun had a noticeably better trigger out of the box in that both of us were able to perfectly stage the pull, which was not possible on his stock 442.
Ultimately, whether it is worthwhile depends on whether you are prioritizing cost or value. A standard 442 or 642 is obviously going to be cheaper and more likely to be the object of sales with deep discounts due to the volume of their production. The Performance Center versions, however, are a great value for a comparatively marginal (~12%-17% over normal prices for mine) increase in price.
About what was wrong with my gun specifically: It looked like it was made on a Friday afternoon or Monday morning. It had tool marks on the barrel shroud, chips on the trigger guard, a spot near the Performance Center rollmark where the finish looked scuffed/was rubbing off, a smudge on the trigger that looked to be caused by uneven application of chrome, poorly mated grip panels, and something that looked like metal fatigue/very bad machining right where it meets the barrel. Most of these are fairly minor issues individually, but I found them to be unacceptable when viewed as a whole.