answering your question...
Yes it can be done. I can get my straights as sharp as nearly any DE blade I have tried. This is shaving with a Shavette and DEs. However, the edge doesn't last and needs to be refreshed and that level of sharp doesn't last forever. My Polisilvers might be better than my best straight edges but it would be a close comparison. I don't ALWAYS get DE sharp with every straight after every honing, but it does happen.