Just looking at the specs, the JH5s have an input sensitivity of 119dB @ 1mW and the JH7s have an input sensitivity of 124dB@ 1mW. The 7s do have dual low drivers vs the 5s single. SO the question is, having not actually listened to either, which would have superior bass? And this may just come down to personal preference, actually I'm sure it would, but it's an interesting question.
Also on a side note, the JH 10 x3 has a low, mid and high and is 799$. The JH 10 is also 799 but it only has dual lows and a single high. Wouldn't it make sense to go for the three separate drivers for the same price? I guess it again comes down to personal preference?