Su-27 (from which the Su-35 is derived) first flew in 1977. Totally irrelevant comparison. In fact it should be a totally irrelevant comparison. The fact they are remotely comparible in any way is a tragic commentary on the JSF programme. Should be an all-aspect stealthy, huge payload-toting, viffing, super-agile, fuel efficient vision-from-the-future, shooting glitter out of its tailpipe on demand for the resources, technology, (international) money and man-hours they've spent on it.
It's simply a product of a fatally flawed design process. Nice business model though. That's been the really clever part.