Using native Tikz tree or forest?

Question

I just have a very philosophical(?) question. At this time i am well in drawing pictures with tikz. Now i have to make some tree-like diagramms and ask myself which "package" i should use for this? In the Tikz manual there is already some sort of mechanism for drawing trees. More, I often heard of the package forest but which have a complete different syntax. Does it make sense to put effort in getting to know "forest" or is it the same as using the tikz mechanism? I dont want to change all of my work later on so I try my best to figure out which option should be used.

So in simple words:
Forest >>>> Tikz?
or ist it just the personal preference that counts and both are great?

EDIT: I want to achieve a "tree" like this one

Is therefore tikz, qtree or forest the best option?

Answer 1

Why to restrict to TikZ-tree or forest? A simple matrix also solves the problem:

\documentclass[tikz,border=2mm]{standalone} 
\usetikzlibrary{positioning, matrix}

\begin{document}
\begin{tikzpicture}
\matrix[matrix of nodes, nodes={align=center, text width=2.4cm},
    column sep=5mm, row sep=2mm] (A) {
&&&{Group 1\\ 300 Subjects}&{Treatment 1\\ Drug X 325 mg}& \\
&{600\\ Men}&{Random\\ Assignment} & & & Compare Drop in Temperature\\
&&&{Group 2\\ 300 Subjects}&{Treatment 2\\ Placebo}& \\
{1200\\ Subjects} & & & & &\\
&&&{Group 1\\ 300 Subjects}&{Treatment 1\\ Drug X 325 mg}& \\
&{600\\ Women}&{Random\\ Assignment} & & & Compare Drop in Temperature\\
&&&{Group 2\\ 300 Subjects}&{Treatment 2\\ Placebo}& \\
};

\draw[->] (A-4-1)--(A-2-2);
\draw[->] (A-2-2)--(A-2-3);
\draw[->] (A-2-3)--(A-1-4);
\draw[->] (A-1-4)--(A-1-5);
\draw[->] (A-1-5)--(A-2-6);

\draw[->] (A-2-3)--(A-3-4);
\draw[->] (A-3-4)--(A-3-5);
\draw[->] (A-3-5)--(A-2-6);

\draw[->] (A-4-1)--(A-6-2);
\draw[->] (A-6-2)--(A-6-3);
\draw[->] (A-6-3)--(A-5-4);
\draw[->] (A-5-4)--(A-5-5);
\draw[->] (A-5-5)--(A-6-6);

\draw[->] (A-6-3)--(A-7-4);
\draw[->] (A-7-4)--(A-7-5);
\draw[->] (A-7-5)--(A-6-6);

\node[draw, below right=of A.south west, anchor=north west, inner xsep=3mm] (B) {Assignment to block is not random};

\draw[<-] (A-4-1)--(A-4-1|-B.north);
\end{tikzpicture}
\end{document}

Update:

Just to show that forest is probably better for schemes more similar to trees. I'm not a forest expert, so it's not perfect: lower Placebo nodes are not equally aligned. I hope someone could help.

\documentclass{standalone} 
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage{forest}

\begin{document}
\begin{forest}
[1200\\ Subjects, for tree={align=center, grow'=east}
    [600\\ Men
        [{Random\\ Assignment}
            [{Group 1\\ 300 Subjects}
                [{Treatment 1\\ Drug X 325 mg}
                    [,phantom]
                    [,phantom]
                    [Compare Drop\\ in Temperature, name=aux11]
                ]
            ]
            [{Group 2\\ 300 Subjects}
                [{Treatment 2\\ Placebo}, name=aux12
                ]
            ]
        ]
    ]
    [{600\\ Women}
        [{Random\\ Assignment}
            [{Group 1\\ 300 Subjects}
                [{Treatment 1\\ Drug X 325 mg}
                    [,phantom]
                    [,phantom]
                    [Compare Drop\\ in Temperature, name=aux21]
                ]
            ]
            [{Group 2\\ 300 Subjects}
                [{Treatment 2\\ Placebo}, name=aux22
                ]
            ]
        ]
    ]
]
\draw (aux11)--(aux12) (aux21)--(aux22);
\end{forest}
\end{document}