He was on the slow side. He largely thrives from a lot of input. Against fighters who are coy? Well we have a problem. Hate to say it but Mayweather would cause him a lot of problems.
i don't think he looks slow pre '52, post comeback he'd lost a step. agree he was better vs agression. nothing wrong with the floyd comment imo, basically everyone below middle would get some problems from him.
He wasn't particularly good at infighting, as pointed out by multiple reporters who wrote about his fights. It's a flaw, because it was exploited by multiple opponents against him with good or decent success. And it became worse because his defensive skills were far from great.
Up until the post 1952 era he was as near as perfect as it was possible to be from what I've read and based on the footage I've seen. Maybe,as has been touched on,he mixed it up sometimes more than what was really necessary.
The guy lost one fight in his first decade of boxing. This was against a great fighter weighing just over 160 while SRR was well inside the Welterweight limit. He never lost a fght at his peak weight, which was 147. He was 128-1-2 when he lost his second fight, at middleweight. He immediately avenged that. So i really don't think this "flaw" was overly exploited, certainly not in his first decade and 130 odd fights.
Defense in general was average. He got hit a bit, partly because he was aggressive. There are articles that he avoided some of the better black fighters of his time. Sugar Ray might have had issues with a taller and longer puncher with a jab. Not sure if he fought a good one of those types.
Great all-round game. Most of Robinson's apparent 'flaws' seemed more to be trademarks of his style rather than faults. He probably held a physical advantage over most of the Welterweights he fought and so would just tie up and hold, at close quarters; rather than persist with short range exchanges. He certainly appeared more comfortable at long range where his reach and footwork served him well. To the best of my knowledge, there is little footage of Robinson at 147. Most of what's seen of him is at middleweight, so it is perhaps difficult to assess his speed as a younger lighter Boxer. The available footage does not show him as being lightening quick, in my opinion. That said, Robinson tended to put a lot on the majority of his punches and his combinations were heavy-handed; not pitter-patter. He got hit a lot more than he needed to but was teak tough in the chin department - so I'm guessing he didn't worry about taking a few. This might be seen as a flaw. Although, again, he didn't entirely abandon his defense and did show he was conscious of being defensively minded, as he looked to close the distance on an opponent.
Rocky Marciano hadn't lost at all. Does that mean he had no flaws? You are saying things that are irrelevant in discussion of whether Robinson had any flaws.