I have found the option to include images in my documents in PDF format to be much more convenient than using image formats such as PNG or JPEG.
At least in my documents (which I compiled with pdflatex), the images were generally better-looking and sharper.
A minor problem with this solution is that pdflatex in my default document setting seems to have issues with PDFs of “newer” versions. While there was no visible defect with the resulting document, pdflatex generated a warning per PDF file included. This warning looks as follows:
PDF inclusion: found PDF version <1.5>, but at most version <1.4> allowed
Although, there are no visible problems with this, I hate to ignore LaTex warning, because I fear that they sooner or later will result in real issues.
Happily, a slight change in my document preamble eliminated the warnings. I just had to set the PDF minor version to the version of the PDFs I included in the document:
This option tells pdflatex in which version it should output PDFs. So, as a nice side-effect of eliminating the warning, my PDF documents are now also of a newer version.