Things I liked: Not much. It was good while it lasted. But louder than advertised.
Things I would have changed: Make it not die after 200 rounds of 9gr. pellets. After 200 rounds of .177 polymags in my Whisper, it lost half it's power. Normally, says the repair dept who received my Whisper for repair, they die outright, mine did not. It lost half it's cocking force and pellets just rolled slowly down range. It did so AFTER the 1-year warranty. So I am out of luck and going back to spring, and paying for all the work to be done. My Whisper now cost me almost twice it's original price, and for what?
What others should know: I think the failure rate on these devices should be published on Pyramid's website. It might be higher than you think.