The only online R&C game I have had the opportunity to play was R&C: Qforce, and I found it great fun. It's a shame it was never possible (and still isn't) for me to play R&C3, Deadlocked and SM.
Oh wait, I played A4O too, but only briefly as there was a really bad glitch that made playing it online barely work… oh well, at least it wasn't like I was missing out on much for that game, it's still just as fun with local co-op and isn't that bad playing solo.
Really if any future R&C games have multiplayer, I'll play them, and probably like them. But I'm certainly not going to complain about it. I also won't complain if there is no multiplayer.
Personally I like Qforce more than Size Matters, although I think I have valid reasons, I accept that most people believe the exact opposite. I found a lot of Size Matters' mechanics were re-skinned less functional equivalents of gameplay we've seen in previous games. A lot like ToD, although I felt ToD had the same mechanics work slightly better with some new ones I liked, whereas the new content in Size Matters' just didn't feel as necessary to me, ad most of the plot went in a direction full of contradiction and was never mentioned again.
All in all, Size Matters tried new things that never stuck with the series, and was ignored by later Insomniac Games, so it felt unnecessary, kind of like A40 and FFA. But I personally liked A4O for what it was, and really liked the new stuff in Qforce.
And no, I'm not blindly rejecting "non-Insomniac Games", although it might seem that way. For example: I liked Secret Agent Clank, and even found the Jak and Daxter game they made a real blast! (Although not as a Jak and Daxter game)
And nope, I didn't even get time to play them - it's shown on the timeline. I asked for a PS2 with the first game for Christmas in 2011 so I could play the classics. But then they announced the Trilogy for PS3 
hope you understand
