Decisions regarding software evolution strategies such as modernizations are economically important. We present results of our empirical study of the views of decision makers. We have asked their views of the relative importance of 49 software modernization decision criteria. We have gathered data from Finnish software industry. There were 26 experts from 8 organizations involved. They were mainly upper or middle level managers. Our study shows that there is a large set of criteria which should be taken into account, and that those studied by us provide a good coverage of the relevant ones. We list the top-twenty criteria. We also performed a cluster analysis which produced two groups of subjects. Views of the decision makers in software user and software supplier organizations were different. We suggest that decision maker's work process could be enhanced by taking into account the received lessons.