I have both and use both. For just monitoring signals as a receiver Airspy R2 is best. But as a spectrum analyzer (using programs for it), the HackRF 1 is much much better. And for serious analysis of signals, the HackRF 1 is far superior--not even in the same ballpark. You can get both for about the same price (the Chinese ones on eBay work perfectly fine--I own 6 and have compared against two from the US source). For HF, the Airspy HF+ Discovery it the way to go for HF and below.