Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Slim design; questionable performance and durability.

I've owned this stud finder for over a year now and use it periodically for various projects. I recall that I bought it for it's small profile and apparent 'pro' qualities. After about a month, all but the two bottom l.e.d. lights stopped working- the 'beep' is the only way for me to know where the stud edge is. As mentioned by others, the a.c. detection is laughable. As for stud detection- yes, it's a dark art even with a finder. I can't say that this unit does better or worse than the many others i've used for this primary purpose.