  We study universality and scaling properties of RG gauge actions (Iwasaki and
DBW2). In the first part we consider the critical temperature T_{c} and compute
the reference energy scale r_{0} for critical couplings \beta_{c} corresponding
to N_{t}=3,4,6,8. The universality of T_{c}r_{0} between Iwasaki and Wilson
action is confirmed and the scaling behavior of the Iwasaki action is found to
be better than the one for the Wilson action. The results for the DBW2 action
show larger lattice artefacts. A continuum value T_{c}r_{0}=0.7498(50) is
extracted. We compute also the glueball masses for the states 0^{++} and
2^{++}, investigate the scaling of m_{0^{++}}r_{0} and m_{2^{++}}r_{0} and
point out practical problems which are due to the violation of positivity
present in the RG actions.
