from the pic , i doubt the effectiveness .

the bar itself is a round shape , which is quite hard ... but the edge there connected to flat shape hinge . flat shape is easy to be bend . try use ur ruler , see easy to bend or not ? ... notmal strut bar has whole construction with two circle on both end which is much more solid and stable in configuration .

the 3 point one is not really good for ur car .
i ahve read before , it must be on that two points only , that is one of the way to make it cancel-off each other forces .
for the one screw into firewall , in long term firewall might have loosen due to forces . ask ppl about this , many 3 point user expreienced .