And I can vouch how much those Ebay bars flex. When I purchased my 1991 Civic Si for autocross duties this year it came with an ebay bar like the 1st one you pictured. Car had -3.5 negative camber in the front. I knew those crappy bars wouldn't do much and got myself a Neuspeed front strut bar which is one solid tubular piece.

When I went to install the Neuspeed bar the bar would not go onto the car - the bar and bolt were about 1" from lining up. It took me about an hour of thinking to figure out to jack up the front middle of the car so the strut towers would move out a little. The Neuspeed bar fell into place perfectly. Went to get my camber remeasured and the reading was -2.8 camber. So it definitely did something.