I bought my Peterson 590 AutoStrobe awhile back to update my piano tuning business to a more mordern (now digital) strobe with some of the newer bells & whistles that are available now-a-days.I have a Conn Strobotuner ST-6 tube type '60's model,And the Conn Strobotuner ST-11 solid state '70's models. So my compairisons are based on 45 years of piano experiance. The Conn ST-11 improved over the previous ST-6&8 tube type of course ,with no warm up time & lighter weight ,but,same basic controls .This new Peterson 590 AutoStrobe Has all of those older controls but , in easier acsess (once you get used to where they are) . The manuel is pretty easy to understand and apply . I expected more presets (tempers and possibly the strech tunings pre-programed) in this "Model 590" but you are limited to the 8 basic temperments.A couple are usefull for the guitar but,really useless for modern piano tuning.The Auto feature will not be useful at all tuning pianos but,the digital cent adjustment IS more accurate than older model Strobes .Not to cut this unit short,I like the push button features & lay-out of the manuel note selection and, the audible tones have been a help at times. All in all, I like the Peterson 590 AutoStrobe for updating to a newer peice of equip.,the digital features are nice ,even though I'm an old analog guy , it does make my job easier and the digitaly controled strobe "IS" easier to read.