I have a cabinet above my hood so that is what determined where my range hood lined up with the backsplash, which is not at a grout joint. I would have preferred that it did line up, though, so if I could choose the position, I would,

I'm kind of a detail oriented person, so given the choice, yes, I would line it up with the next grout joint above 30", or maybe even one more full tile.
I mounted my chimney island hood at the max 36", to keep it above head banging and sight line... Chris

I would line it up if you can. If going a little lower means someone will bang their head, go with a little higher. The total increment is only 3" with a subway tile, so a partial up or down shift of less than 3" should not have much of a negative effect either way.

I agree with previous 2 posters.

Just had to post - are you over-thinking this? --- nah! I beginning to wonder what I'll wonder/over-think when kitchen completed. :-)

When it comes to certain things like this, if you can control a detail, I don't think there is any such thing as over-thinking it.

Of course I am renovating three bathrooms and designing them all from the framing stage so that they are mostly all full tiles, and grout lines line up the way I want them to, all over the entire bathroom. So I am not the person to ask.

Thanks for the feedback!

Mine is lined up and it looks nice to not have a partial subway tile at the top IMO.