Hi,
I am sorry not to be much helpful, but I am having exactly the same doubt as you. So if anyone could just drop a comment on this topic ... I would be very grateful.
Anyway, it seems to me that Sony is a bit better once HC62 has 1MPixel CCD instead of 800k, it supports two video firewire ports, one for input and the other for output, instead of output only (USB). Besides that, every sony models have nice features like touchscreen, time lapse,....
Maybe this GS90 should be compared with HC53 or HC51, rather tha HC62.
What I don't know is how it performs in what concerns to image quality....
Best regards,
Pedro Cardoso