Both are equally good. I have a Stihl FS90 for a few years and it's been super reliable. Just picked up a used Shindaiwa 242 package that is also great. It includes an AH Hedge trimmer, string trimmer and both long and short shafts. Really like the balance of the hedge trimmer with short shaft.
Used Stihl's seem to bring better prices on Ebay and CL.