I have both, though I have only had the carbine for a couple of months and haven't had much opportunity to test it out as yet. Still, it's light and handy, and the one 30-round after-market magazine I have for it has been reliable so far.
For most folks, if your M1 isn't beat to Hell, and is reliable with your chosen magazines and ammunition, I can't see that you are giving up much in practical terms. Energy is a little less, but still very respectable. Range is a lot less, but in and around the house, that's not an issue either. It will do the job and do it well.
One thing that confuses me is when so many people reject the idea of getting one or another gun simply because of a lack of accessories. I guess I am just different, but, if I want a gun, I want it "as is" for the most part. I don't make lots of changes to it. Sure, AR's have the benefit of being easily built, serviced and modified by the end-user, and American industry has provided a plethora of - sometimes outright strange (A crossbow? Sure! A .50 BMG single-shot? You bet) - modifications, but unless the user has some really special needs, it's usually just gilding a lily.
Another thing is that, while I enjoy my AR, especially being able to drop-in the CMMG .22LR conversion and shoot it anywhere, AR's, despite their customizability, have become so common that nobody seems to want anything else. I'd love to see some more options to fill that niche. For example, maybe a version of the Remington 7400 that takes AR magazines? Maybe it wouldn't be profitable, but I can dream.