Aquaplas vs. Coosa

[Maine Priority]

Hi everyone. Its been awhile since I posted on here but the Spring boat project and the warmer weather (40*) has got me anxious to start the transom build. I plan on ordering my transom bracket in the next few days and believe I will go with a HERMCO bracket. My question for everyone, and I'm sure this has been kicked around at length so please don't shoot me is the best transom coring material. Coosa board seems really good but is also 3x more expensive and thats before shipping. The Aquaplas is 1/3rd the cost so Im wondering is one as good as the other (ford vs. Chevy) kind of thing. I only want to do this once and have settled on spending more for a better end product. I plan to use epoxy, either System Three or Marinepoxy for the build because of their low viscosity and wet out properties. I am steering away from marine ply for nothing more than piece of mind and knowing that if I do mess up I won't have the equivalent of a sponge in the transom.
What makes one better than the other and why?
Thanks in advance for your input and understanding

[Fuzz]

I have never used either one of them so I am interested in what others think also. I did see where JM said to use aquaplas 3 if that is what you use. Probably worth a phone call to BBC and speak to them directly to see if they have a preferred way to go.
After replacing a couple of transoms I understand the lure of not going back with plywood but I have to ask if it is worth it. The old transoms were put in with cheap plywood and poly. They lasted for 25-40 years. At 61 I do not think I will need to worry about redoing them in 30 years if good plywood and epoxy are used:lol:

[fallguy1000]

Not to confuse, but I used corelite on mine.

28#

3/4" x2 glued with epoxy and cabosil with a vee trowel and vac bagged with 9" hg

I find the corelite to be a tad brittle, but that is versue corecell, not another 28" foam. Price from Canada was good.