I always thought my first baby would be a girl, don't know why but we had a name picked out & everything, then when we had the u/s it was definitely a boy there was no questioning those boy bits. I have to admit I shed a tear & my DP was a little disapointed for just that first moment. Then we started to think of boys names & how he would follow his daddy around & be a fisherman, handyman etc... & the excitement grows. Now 7 mnths later & I wouldn't swap him for a girl for anything.
About the nappy changes I find a toy to distract him helps, you don't pull the skin back or anything just move it about to clean the poo off etc... someone who has girls said there are no flaps for the poo to hide in so it can be easier than a girl in that respect
I can't tell you much else about the difference oh one more thing there doesn't seem to be as many boys clothes as girls but you can always find something cute.