Thank you for keeping this conversation from getting too heated...you ladies are awesome.
I totally understand how difficult it is to have a needy/fussy baby, especially when you have other kiddos to take care of. I'm sure most (if not all) of us have had to let our kiddos cry at some point, either because we were driving or otherwise engaged. It's just not possible to hold them 24/7 and I think that's fine. I also agree with Prudence, that since you have two, they are going to need more/less attention at different points of their lives, and that's ok too. You shouldn't feel like you're neglecting one because the other needs you more at that moment. I'm sure they know they're both loved equally.
I'm not a fan of CIO but that's my own personal opinion and I certainly understand why it works for some families and respect their right to choose that path. I think you know what will work best for you and your kiddos so you need to trust your instincts. I do agree with the others though that true CIO (where you leave babies alone to cry) is probably not best to do with kiddos this young (most articles I've ever read advise not doing CIO before 6 months), as I don't think they can fully self-soothe the way older kids might, but allowing them to fuss a bit might work for you if you need a break to attend to the other baby.
Good luck, I can't imagine how hard it must be for you with two infants to care for, especially when one is high-needs.
Lenora & Chris 01.16.10
DS Brandon 05.13.07
DS CJ 10.06.11
*Co-moderator of January-June '07 and September '11*
To the OP, I don't think it's CIO at ALL if you're tending to one child because they need something, and you've done what you can for the other one (place in swing, binky, etc.) and are just finishing taking care of one child, and will tend to the other one as soon as you're finished.
I'm close to anti-CIO, and I have had to do this! I have a 17 month old and a 3 month old. For example, yesterday morning Damien was very tired, and I had spent 2 hours trying to get him to sleep. He wouldn't sleep. My 17 month old was screaming at me because he had a stinky diaper. I had to put Damien in the swing while I changed Jonathan - as I had no choice (to take him in the room with me would have been even worse on him). He screamed and screamed and became very sweatty and his face was bright red and he had alligator tears. I wasn't intentionally neglecting him (which is what CIO is - intentionally letting them cry.), I just could not console him at that moment, as Jonathan's diaper was more of an emergency.
Have you considered, or do you babywear? Perhaps that can give you a way to be able to hold both babies at the same time, if only for a few minutes.