How confusing is it when looking for a new battery?

Aux battery died.

Been researching and ringing around most of day and wow, what a diverse range of, often contradicting, advice.

Am considering the Supercharge Allrounder. So would appreciate comments from those using one as an aux. battery.

Will essentially be used to run a Trailblaza fridge and a bit of lighting. Have a few others things but they rarely get much use. Our camping style is mostly overnighters with variable distance/time between stops ie some long days, some short. However we sometimes stop for a couple of nights and then there's usually not much travelling involved during the day. Have a Redarc system to isolate batteries when stopped. Starting battery is a Bosch maintenance free unit.

Concerns/questions re Allrounder are:
* can it handle the heat under bonnet OK (V8 petrol Cruiser)?
* will it run fridge OK for a couple of days?
* being dual purpose I assume it will charge up quicker than a 'real' deep cycle?
* does it handle vibrations OK?
* have been told that being a dual purpose battery the real AH capacity is less than the stated 105 AH. The guy reckoned a dedicated 105 AH deep cycle was a genuine 105 AHs whilst the dual purpose ones only have about 50 to 60 AHs in them for deep cycle purposes. Is that true?

Any other comments appreciated.

Thanks in advance.