I can help you to clarify the question. You need to add pst-eucl in your question. The most important thing is
Because I want to create several similar shapes and I do not want to
go back and to fix them can you tell me in your opinion which method
offers me more possibilities - options.
Part 1) __Tikz Pstricks tkz-euclide pst-eucl__
Firstly you can't compare my little package tkz-euclide with main packages like Pgf-tikz and pstricks.
On one hand tkz-euclide is a package based on Pgf-tikz and on other hand pst-eucl is a package based on pstricks. These packages allow the drawing of Euclidean geometric figures using macros for specifying mathematical constraints.
If you want to create several similar shapes you need to make a choice between a general tool like pgf or pstricks and a specialized package like tkz-euclide or pst-eucl.
I agree with Herbert, it's not easy to give a correct answer. I can only say that I prefer tikz because I like the syntax, the documentation but this is just my opinion and these arguments are not necessarily objectives. Perhaps you can also find it strange that my package syntax is different from that of tikz. To understand why... I can also tell you why I wrote tkz-euclide.
My idea was like you to create several similar Euclidean geometric figures. A fine tool was pst-eucl so I decided to create a similar tool based on tikz. There are a lot of similitudes between pst-eucl and tkz-euclide. I made a mix ... the names of the macros are based on pst-eucl and the options are based on tikz. The syntax is also a mix.
An important thing is that you can mix tikz and tkz-euclide (see my answer on your first question)
Conclusion : tkz-euclide is a tool to create similar geometric figures without knowing the complete documentation of tikz. And it's the same thing for pst-eucl and pstricks.
Part 2) Update __let operation vs tkz-euclide__
The question is now ore precise. In a perfect world, tkz-euclide is unnecessary. A fine solution would be to write a library euclide to provide some useful tools to get geometrical figures with simple codes. I wrote the first version of tkz, before some libraries of pgf/tikz without the let operation without the intersections library. Now I need to update the package to add new macros for the user and the possibility to use name path and something like let.
Some disadvantages of tkz-euclide
a) The package is based on tikz but the syntax is different
b) if you work with tkz-euclide, you can't use something like let or name path. It's possible to mix syntax and codes but I agree it's not satisfactory.
c) Like Tikz calculations depend of TeX and it's a bad thing. Perhaps lua can change a lot of things. I agree with Garbage Collector, Pstricks with postscript is more powerful to make complex calculations.
Advantages
If you only want to draw geometrical figures the package can facilitate the creation of severals shapes.
If you want to use tikz
A recent example (yesterday), the next code shows a bug :
\documentclass{article}
\usepackage{tkz-euclide}
\usetkzobj{all}
\usetikzlibrary{through,intersections}
\begin{document}
\begin{tikzpicture}
\tkzInit[xmin=-0.5,xmax=14.5,ymin=-0.5,ymax=7]
\tkzClip
\tkzDefPoints{0/0/A, 13/0/B}
\tkzDefMidPoint(A,B) \tkzGetPoint{M}
\tkzDefLine[orthogonal=through B](A,B) \tkzGetPoint{C}
\tkzInterLC(B,C)(B,M) \tkzGetSecondPoint{C}
\tkzInterLC(A,C)(C,B) \tkzGetFirstPoint{D}
%\node [name path=ci,circle through=(B)] at (C) {};
%\path [name path=A--C] (A) -- (C);
%\path [name intersections={of=ci and A--C,by={D}}];
\tkzInterLC(A,B)(A,D) \tkzGetSecondPoint{S}
\tkzDrawSegment[color=red](A,S)
\tkzDrawSegment[color=blue](S,B)
\tkzDrawSegment[thin](A,C)
\tkzDrawSegment[thin](B,C)
\tkzDrawArc[delta=10](C,D)(B)
\tkzDrawArc[delta=10](B,C)(M)
\tkzDrawArc[delta=10](A,S)(D)
\tkzDrawPoints(A,B,C,D,S,M)
\tkzLabelPoints[above left](A,B,C,D,S,M)
\end{tikzpicture}
\end{document}
The result seems to be fine but if you look at the figure in B with a zoom, you see that :
It's probably a rounding error. The mistake comes from the macro \tkzInterLC. A solution is to use some codes from Tikz, an I can replace : \tkzInterLC(A,C)(C,B) \tkzGetFirstPoint{D} by
\node [name path=ci,circle through=(B)] at (C) {};
\path [name path=A--C,red] (A) -- (C);
\path [name intersections={of=ci and A--C,by={D}}];
You can see that the code from tikz is very different and less concise.
This is ironic. I used the fp package with the tkz packages to avoid these kinds of problems (there are other problems like this with tikz) but it seems to be insufficient.
Conclusion. Tikz is very useful for a lot of things and I think it's a good idea to study this tool. If you don't have a lot of time and if you want to draw only geometrical figures tkz-euclide can help you. It's obvious that it's possible to draw all the pictures with
only Tikz but sometimes it's not easy when you want to draw complex figures (but Tikz is not a mathematical tool !).
