Eh. Sega's consoles? Most advanced of their generation? That all rather depends on what you're comparing them to.
For instance, if you consider the dreamcast part of the same generation as the original Playstation and Nintendo 64, it looks powerful.
But if you lump it in with the gamecube, PS2, and Xbox, suddenly it looks a little less impressive.
I can't say much for the saturn, although what I just read does suggest it might be quite powerful.
The Genesis VS the Super Nintendo is a much more difficult comparison though; - While the Genesis is faster (and thus can deal with high speed action games somewhat better), the Snes appears to have noticably better graphics hardware, with a much larger range of colours, and the ability to easily pull off colour blending operations.
But that nitpicking aside, it is something of a puzzle as to why Sega seemed to struggle so much in the console wars.
The only console that did well is the Genesis/Mega Drive, and even then it was a geographic split with the Snes (Snes was ahead in some countries, Genesis in others). The end result on a global scale being something of a draw.
But the Saturn was almost a complete failure... The Game Gear died out really quickly, The 32x and Mega CD were both failures, and the Dreamcast didn't fare too well either once the competition actually showed up.
It's difficult to understand where this came from.