I,m in San isidro but nerarer the Pan Americana,however have a look,if yiou want really nice burgers Pepino,s is good
http://www.baenjoyit.com/sanisidro/gastronomia/gastronomiaSanIsidro.html
you,ll be 2 blocks from the parilla Las Tipas,give it a try,and you can let us know.enjoy