The only thing Saints Row did better is by adding a bunch of useless features. If Rockstar had left off where they did from San Andreas they too would have added a bunch of useless features.
Unfortunately they decided to NOT follow San Andreas' footsteps. They instead removed features and worked on other areas like,graphics,physics,and detail. I myself am a modeler and can appreciate the amount of work put into making the GTA 4 city. You can tell that in Siants Row 2 they just copied buildings and textures all over the place to fill things up.
To summarize what I'm trying to say in Gta 4 you can go to the middle of the city and stare at beautifully modeled buildings, amazing car models and physics, and an astounding amount of adverse and active pedestrians. In Saints Row you won't see any of that, but you can get in a side seat of a car and shoot rockets!
It really depends what kind of gamer you are. Personally I would love to have both scenarios. But if I have to chose I'd rather play a game that has style and grace than one that was made to keep ADD kids busy for long periods of time.