I havent personally used both, but can tell you OF is hotter than HF, so it will last longer in feeding your plants. HF has added benes for seed starting and root health for young plants, but has less amendments to keep them alive in veg. Take your pick.
I just transplanted into Happy Frog and love it. I have also done grows using Ocean forrest and thats some good shit to I just get more bang for my buck with Happy frog.
My last grow i went from mg to OF .there was a big diffrence for me anyway . my left over OF i used to transplant a half dead house plant .The house plant has exploded! But my exp. with OF and marijuana have been faired with very happy results . Now im messing with coco fiber see what thats about.. But i wont use anything other than OF and would really like to try some HF.. Also i did add some perlite to the mix ,but i think its pretty good without adding more..
i mixed them together and got great veg this stuff is high in nitrogen, try roots organics its high in phosphorus and you get better results in your flower