YANBU, although your DH is, of course, entitled to a say.
One thing I will say, though, is that with dd1, I believed all my aunts etc telling me that unless I moved her out at 6mths, she would get clingy, it would be impossible etc. So I did, and it was HELL. She became far far more clingy, and refused to sleep unless I was in the room, preferably holding her hand. I was so sleep deprived I was sitting there half the night weeping. Even when I did creep into my own bed finally, I lay on tenterhooks waiting for her to cry out. No way was DH getting near me anyway- I was alert to every creak of the cot, every snuffle, every little noise she made (she was through the wall- sometimes I had such a strong desire to cut a hole in the bloody wall, just to be near her!) I spent many nights lying awake crying, and that and my sleep deprivation affected our relationship more than a sleeping baby in the room would have done.
When dd2 was born, dd1 was only 17 mths. I was too shattered to go through the whole thing again, and didn't want her waking dd1, who remained a "bad" sleeper. So dd2 came into our bed for feeding and sometimes stayed there for a bit, and sometimes went into her cot in the room. My God- soooo much easier! I was so much happier, she was so contented and we all got so much more sleep! When I finally moved her in with dd1 (when she was about a year), she continued to sleep well (better than dd1!) and the transition was really smooth.
Repeated same thing with ds- we had to build him a room, so he stayed in with us (in cot/ bed whatever) until he was around 15 mths. Again transferred to his own room with no trouble whatsoever.
When I look back, I feel awful about how we tried to "teach" dd1 to be in her own room, because it went against all my instincts and made me a jittery unhappy and knackered wreck, and she never settled as easily as the others did anyway, so pointless in the end, for us.
That's just my experience, though- i'm not saying that that is how it would be for everyone! Obviously several people on this thread found it no problem, I think it is because it went against my gut and it wasn't a natural transition that it went so wrong for me. But I'm just trying to point out that your own instinct is more important than other people's experiences!