The fact that R3 has no health regeneration on the SP has me a bit skeptical. Ever since COD4, health regen has been the gold standard in next-gen games. Playing without it, after playing so many games with it, is a major burden and quite annoying. No health regen is like taking a step backwards in the gaming world. Personally I don't give a flying funk about realism in video games (unless we are talking physics and graphics), I just want to have fun. Always worrying about my health being too low or trying to find health packs during a intense situation in a game is NOT fun.
I recently played Singularity, which has no health regen, and that was one of the most annoying and frustrating parts about the game... constantly having to find health packs and healing yourself.
COD4 really popped the gaming worlds cherry, and whether you like the COD games or not they have the formula down. This is something non-COD devs are still struggling to comprehend, they often grab things from the COD games that shouldn't be copied (like making everything overpowered in their online MP game), while leaving out the most important aspects such as solid controls, aiming, consistency and the basic structural foundation which makes the COD games so popular.
I fear that Insomniac, like many other devs have done with some more recent and upcoming games, copied all the wrong parts from COD in an attempt to get some of the COD crowd to their title. In effect this just makes the game a COD ripoff that doesn't even do what COD does so well. I believe R3's multiplayer is doing exactly this and will end up flopping and gasping for air early after the games release, just like KZ3.
It is truly sad what devs are doing to games nowadays, as it seems most of the 2011 release games are sub-par compared to their predecessors. This is typically because the devs change the games so much to try and copy all the wrong things from COD, or because they fail to realize people liked the previous game because of how it played, but the devs feel they need to change everything in their newest game for some unknown reason. Not sure what they are thinking. "Hey, people really liked our previous game, so how about we change everything for our next title!" Makes no sense to me.