I should have known that "Renewed" is always a bad compromise. 4 years of usage and frequently update and maintenance, this junk has "shut itself down" for too many times that I could count, and any report to Apple is useless and empty. It has memory allocation issue and for a while it seemed like it was resolved, and of course new problem arose. Something keeps interfering with using wifi/ethernet at highest speed. I know this because I am software engineer and I tested and tried to isolate issues that could relate to my network (modem, router, switches) while side by side comparing speed test and jitter with another macbook of mine. I do not recommend this product.