@zachariahs I'd lean towards the semi D.
Though modern houses are (usually) well made, so noise shouldn't be much of a problem in the mid terrace, the semi D is just one neighbour to worry about.
The small walk in wardrobe wouldn't sway me.
The second ensuite wouldn't either. You likely have one in your master bedroom which is the most important thing. If you have one kid using another bedroom, they may as well have their own ensuite since they won't have to share the main bathroom.
For visitors, it's a mild extra convenience that'll be used a few times a year. It'll sit empty and unused the rest of the time.
The utility room is a bit of a pain though. It's a weird config of an estate that the mid terrace has so much more space, but the pros of dedicated parking, side access, one neighbour would make me lean towards the semi D.