I've got a Stihl FS450, a 550, and the Husky 555FX. The husky gets my vote, it balances so much better in the harness than the Stihl's and can be used for much longer periods without fatigue. For taller people like myself the Husky Balance XT harness is the most ergonomical. The higher end Stihl harnesses are comfortable, but not made for people over 6 feet tall.