EFB camper batteries -- has anyone used them?

From what I understand, you don’t get more run time (amp-hours) from EFB’s, you get more cycles, I.e. - they last longer (more years) before they go kaput.

my buddy has them in his camper, they work but he still only has 180ah between the two so in reality about 90 usable AH.  he is looking to change to LiFePO4 now though to get more AH in the same amount of space.  

EFB are flooded batteries , just have some reenforcing and such, to make them a little stronger and resistant to vibration and they claim more cycle life but don't list anything for it.  also what makes me sceptical about them is that they list CCA of 800 amps which means it leans towards more of a hybred deepcycle/starting battery rather than true deep cycle.  they do show that it should get 400 cycles if you stay to a 80% depth of discharge so if you want that you would have to keep your usage down to 72AH/battery (assuming a group 27 with 90AH capacity) or you start to ahorten that life.  if you stay at around 50% like I said above (45ah/battery) then you would probabaly get a longer life out of them.  

I know you said you didn't want LiFePO45 as you would have to change the converter section, did you look into what that would cost.  it really isnt much to buy an external charge and get some one to install it for you if you are not comfterable with it.  then if you buy premade batteries you could get two that would fit and give you over twice the usable power you have now probably outlad your camper, but thats just a thought, the other is to measure a 6V battery at costco and see if they will fit.  thats cheeper than what your looking at and will give you a little more power but way more cycle life