Hi Dave,
I have used the flat hardness for a couple of years for both popping n jigging and i would say they do a great job for me of not shifting left to right nor worry about the gimbal popping out for nothing. Another good thing is the cup is pretty big so getting the rod butt in and out is a breeze. This is my go-to belt
and i do not think you will regret it. If you have the luxury of trying out any fisho's flat hardness for fit and comfort, that would certainly help a lot in your purchase decision......
1. The cup depth is approx 1cm deep (did not take out my belt to measure). I would suggest using only rubber capped gimbal else u will scratch the cup badly as the cup is made from anodized aluminum. All my rods are rubber capped butts thou so no issue.
2. Personally i wear my belt a little lower, 3-4 inches or so below my belly button resting on my groin/hip area. This helps me distribute the load more evenly and allows me to grip higher on the foregrip during a fight (more leverage)
3. I do not have the exact weight but it is definitely light if not the lightest i have come across. The whole thing pack flat too and that allows easy and efficient packing in your tackle bag or luggage.
4. It is not too difficult to find, i would say. But yes, price of it is high now with the soaring yen.
For light tackle... how light? if on the lower end you can get away with a fisherman pad or similar.
Alternatively, You may want to take a look at the JM Master GT gimbal belt. I have not used this before but it looks of the same "concept" as the flat hardness through pictures and is friendlier on the pockets too.
Hope this helps
Cheers,
Kai