Echo's like late model Stihl's all need 'breathed on' a bit, the 590 is no exception, why I'll modify the intake as well as the exhaust before I use it. At least the little CS top handle was easy, just replacing the stock CAT muffler with a non cat muffler (Forrester after market) woke it right up, that and removing the EPA mandated mixture limiters. The 590 has an issue with a poor sealing air filter that allows dust to get into the carb but you can get a foam replacement filter that fits under the hood that eliminates that issue, or you can go the 'O' ring route to seal the stock filter for less.
You can also fit the larger bore carb from the next bigger saw to the 590 for even better breathing, something I may do along with the larger coil and increased rev limiter at some point.
Their weed whackers are no exception either. Severely restricted mufflers, much like Stihl and Husky.
Shindawa and Echo are one and the same, built in the same Japanese factory and everything is interchangeable.