The HCl is definitely less troublesome than a total alkaloid extract - with the TA the nausea and discomfort (especially associated with physical movement) is markedly increased. Ataxia might also be increased.
With that said, the TA is touted provide a heavier, comprehensive experience, which some report includes deeper visions (remember, iboga is all about going deeper, and deeper)... - and is also in line with "traditional" iboga use (breaking open the head and takes advantage of the whole plant.)
When I take a flood dose in the future, I'll probably shoot for a combination of these two. Why? Because my only prior experience flooding was with strictly HCl, and now I feel compelled to dig deeper and see the whole of the eboka vision (especially considering so many of my visions had to do with my relationship to the vegetal world.)
"The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents." -lovecraft