Consider the solution https://tex.stackexchange.com/a/12762/4011 to the problem of fixing the height of a cell in tabular. This essentially adds some space above the cell content, so it is not warranted that it is always vertically centered. Just changing p-cell to m-cell doesn't solve this. So how can I modify this to ensure a vertical centering of the every cell content?
\documentclass[a4paper]{article}
\usepackage{array}
\begin{document}
\newcolumntype{C}[1]{%
>{\vbox to 5ex\bgroup\vfill\centering}%
p{#1}%
<{\egroup}}
\begin{tabular}{|c | C{3cm} | C{5cm} |}
\hline
Short Text & Short Text & Short Text \tabularnewline \hline
Short Text & Short Text & Loooooooooo oooooooooooong Text \tabularnewline \hline
Short Text & Short Text & Loooooooooooooooooooooong Text \tabularnewline \hline
\end{tabular}
\end{document}