una tabella particolare

Salve ho un problema con la seguente tabella
è possibile migliorare il secondo ed il quinto blocco?
`
\documentclass[10pt,a4paper]{article}

\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage{multirow}
\usepackage{booktabs}
\usepackage{tikz}
\usetikzlibrary{decorations}
\usetikzlibrary{shapes,arrows,trees,positioning,through,intersections}
\usetikzlibrary{shapes.misc,shapes.geometric,shapes.symbols,shapes.geometric}
\usetikzlibrary{shapes.gates.logic.US,shapes.gates.logic.IEC}
\usetikzlibrary{patterns}
\usetikzlibrary{shadows}
\newcommand{\tasto}[1]{\tikz[baseline=-.5ex]
\node[fill=white,drop shadow={shadow xshift=0.5ex,shadow yshift=-0.5ex,fill=black,opacity=0.75},rectangle,draw,minimum height=.6cm,minimum width=1.2cm, rounded corners=2.0pt,inner sep=1pt,font=\sffamily] {#1};
}
\newcommand{\tastosetup}{\tasto{SETUP}}
\newcommand{\tastoSndF}{\tasto{2ndF}}
\newcommand{\tastomode}{\tasto{Mode}}
\newcommand{\tastoDGR}{\tasto{DGR}}
\begin{document}
\begin{tabular}{ll}
\toprule
Tipo & Impostazioni \\
\midrule
EL-503W & \multirow{8}{*}{\begin{tabular}{ll}
DEG &\tastoDGR \\
RAD &\tastoDGR \\
GRAD&\tastoDGR \\
\end{tabular}} \\
EL-501X&\\
EL-509X&\\
EL-531X&\\
EL-531XH&\\
EL-531TG&\\
EL-531TH&\\
EL-531TS&\\
\midrule
\vspace*{30px}
EL-520TG&\multirow{2}{*}{\begin{tabular}{ll}
DEG &\tastoSndF\tastoDGR \\
RAD &\tastoSndF\tastoDGR \\
GRAD&\tastoSndF\tastoDGR \\
\end{tabular}}\\
EL-520XG& \\
\midrule
EL-506TS& \multirow{18}{*}{\begin{tabular}{ll}
DEG &\tastosetup\tasto{0}\tasto{0} \\
RAD &\tastosetup\tasto{0}\tasto{1}\\
GRAD&\tastosetup\tasto{0}\tasto{2} \\
\end{tabular}}\\
EL-509TS&\\
EL-520X&\\
EL-546X&\\
EL-W531G&\\
EL-W531H&\\
EL-W531HA&\\
EL-W531TG&\\
EL-W531TGGR&\\
EL-W531TH&\\
EL-W506XS&\\
EL-W531X&\\
EL-W531XG&\\
EL-W531XH&\\
EL-W535&\\
EL-W535X&\\
EL-W535XG&\\
EL-W550XG&\\
\midrule
EL-9950G&\begin{tabular}{ll}
\toprule
DEG &\tastoSndF\tastosetup \\
RAD &\tastoSndF\tastosetup \\
GRAD&\tastoSndF\tastosetup \\
\bottomrule
\end{tabular} \\
\midrule
\vspace*{25px}
EL-W506X&\multirow{2}{*}{\begin{tabular}{ll}
DEG &\tastoSndF\tastosetup\tasto{0}\tasto{0}\\
RAD &\tastoSndF\tastosetup\tasto{0}\tasto{1}\\
GRAD&\tastoSndF\tastosetup\tasto{0}\tasto{2}\\
\end{tabular}}\\
EL-W516X&\\
EL-W516X&\\
\bottomrule
\end{tabular}
\end{document}

`
grazie per il vostro tempo
claudio