I've got the big brother to that radio(357 DX) W/ SP-1A installed by Bob, and yes, they're impressive radios for sure. The only minor complaint I have is there's no way to check SWR without hooking up an external SWR meter inline. That could spell disaster if you don't have a way to check it every so often. Oh-well. Other than that, I've gotten nothing but great reports on how it sounded, especially with the SP-1A on.