The 750 probably sounds better but considering it's got much larger speakers and a much larger radio, that is to be expected. I think reception wise off the antenna like you did, it's a pick em. The 750 should do better on LSB and USB because the 750 pulls each one separate while the 600 is both USB/LSB at the same time, thus doubles the noise. For seperate on the Tecsun, you have to go up to the 660 and above (680, 880, 990 or the 330). Be interesting to see which one handles a longwire antenna better.
The 750 probably sounds better but considering it's got much larger speakers and a much larger radio, that is to be expected. I think reception wise off the antenna like you did, it's a pick em. The 750 should do better on LSB and USB because the 750 pulls each one separate while the 600 is both USB/LSB at the same time, thus doubles the noise. For seperate on the Tecsun, you have to go up to the 660 and above (680, 880, 990 or the 330). Be interesting to see which one handles a longwire antenna better.
I have tried the long wire on both I think the long wire works better on the 750