Welcome to the group. I've been a radio scanner and HF enthusiast since high school (1973-1977), where I belonged to the high school run radio station, WMTH (a whopping 10 watts
My primary interest is digital. I love to search for and if possible, identify and decode digital signals. Despite the constant technology improvements, there are still many digital signals to find on the bands, interleaved with everything else on HF. You'd be amazed at how much various military organizations still use HF for. While satellites and other encrypted terrestrial communications are widely used, the HF band and encrypted data via radio on HF is used because the receiving end communications target requires lightweight equipment, i.e. an SDR radio and laptop, tablet or phone. When it comes to communication in the field, it's hard to beat HF radio for easy reception, quick equipment setup and portability.
There's plenty to listen to above HF as well, but it's more for short distance communication. These newer SDRs, like the RSP, provide the ability to listen up there as well. I have several SDRs that cover HF up through the low GHz range (e.g. Ettus B200: 70MHz - 6GHz, Lime SDR (to be shipped soon): 100KHz - 3.8GHz, Airspy V2: 24MHz - 1.8GHz, and finally the RSP V2). I also have a few HF/VHF SDRs (e.g. WinRadio G33DDC, RFSpace NetSDR, Afedri 822x dual-channel).
I knew SDR technology was going to change the radio world, even when it was simply only 24-bit wide IQ data using a crappy sound card for decoding. I exchange / upgrade my SDR collection as new radios become available. There are few SDRs that I haven't tried or owned over the recent years.
Your QTH is EXCELLENT for pirate and DX work. I'm envious of your general radio location. I live just outside Atlanta, in a very small town about 30 miles southwest of Hartsfield airport, Senoia, GA. It's not the ideal location for radio monitoring, but there are still lots of signals to hear.
BTW, your receiving setup is FANTASTIC! The Wellbrook antenna can't be beat for noise reduction compared to most other antennas. I had something similar for many years, the Pixel Technologies PRO-1B loop antenna. It's performance is similar to the Wellbrook. While your longwire with 9:1 balun might pick up more signal than the Wellbrook, it will also pick up considerably more noise. I'm guessing that you use the Wellbrook more and the longwire only for those tiny signals that just can't be dug out of the noise on the Wellbrook. Am I right?
Once again, welcome to the group!
Best regards and 73 -