Have had my HP since Friday night. I'm not new to scanning; my first was a BCT200XT handheld, which I've owned for over 20 years.
I've already posted elsewhere about not initially finding the micro SD card (which was in its slot all along.) Other than that, initialization went without a hitch. I have a scanning antenna in my attic, and used a BNC adapter to connect to it.
Setting my range for 10 miles, I was blown away with all the signals I was receiving. (Living 25 miles from the NY Metro area responsible for that.) Adjusting the range downward, and avoiding some groups that I wasn't interetsed in made the scanning more manageable. Still have much to learn, like how Sentinel interfaces with the HP.
I'm also not sure I'm receiving all the marine channels. I created a Favorite with them, but its been fairly quiet, even though I live close to the approaches to New York. My previous scanner was good in this area. Could be the weather. We'll see.
BTW, love the portability of the HP. Bought the Radio Shack 800 mhz antenna, and after moving the HP into my living room, picked up lots of activity on the NJ State Police frequencies. Much better than with my attic antenna.
Overall, I'm very pleased w/ the HP, even though my town's police went encrypted last year.