I'm currently spending the weekend at an extremely stormy Smøla island together with OJ Sagdahl, Ole Forr and the host, LA2XPA Rolf Torvik. I have had the chance to compare the receivers mentioned before, and the results were not very surprising. Inexpensive SDRs may in some instances be a good alternative for the dedicated MW DX-er, but if the signal levels are high, the Perseus shows its might. That said, the HF+ did remarkably well. Here's the write-up.