We don't do controlled crying in the official sense of the word- more like, if our little girl grizzles when she goes to bed, we check that she's okay, not got herself stuck somewhere in the cot etc, and then allow her to self settle, which she does with in a few minutes, usually. I know the difference between a grizzle, & a cry, & I would never ignore a real cry- as mummies, we can usually work out whether there is a problem or not. I have a very happy, well rested baby, & she certainly seems not to be distressed by being allowed to grizzle for a little while.
I think we also need to remember that, regardless of the parents sleep being interrupted, babies need their sleep too! Overtired babies are unhappy babies, & as parents, we have a duty to teach our children how to rest. Everyone has sleep cycles, which mean we, apparently, wake several times a night. We simply resettle ourselves, & go back to sleep, & don't remember it in the morning. Babies do exactly the same, except that they don't know how to resettle themselves. Taking baby out of their cot will wake them even more, & they will not learn to resettle themselves. Therefore, they will have a very broken nights' sleep, & will likely be tired the next day.
I'm sure that leaving a baby screaming in their bed for hours on end long-term is damaging- it probably wouldn't work anyway, as baby would likely develop an association with being scared/ unhappy in their cot. But they say it takes 3 days to break/ introduce a routine to a baby, & I'm sure that's not long enough to do any damage.
It's obviously not a decision you have taken lightly, & you have done it with your little ones best interests at heart, & so you should be proud of yourself.