Saints Row the Third was pretty high rated but it was merely "okay." While the gameplay and graphics were better than Siants Row 2, the best parts of Saints Row 2 didn't make their way to Saints Row the Third. Basically Saints Row 2 was terrible gameplay with some good missions and side content, while Saints Row the Third was good gameplay with terrible missions and side content.
If there was a mix between the two, good gameplay with good side content and good missions, then they'd have a great game. From how quick this game was developed, I'm really not expecting much.