Well, I have been using these "cuties" for the last several missions, and they do come in handy sometimes.
However, I have noticed a bug with them.
I was just on patrol in area A4 when I found a convoy leaving port,
Using my radar, I went the long way around an island, and managed to get ahead of it. I was positioned about 1500 yards from the projected path.
Long story short, I sank 5 ships, 3 merchants, and 2 DD's. However, it was when I sank the DD's that I noticed a "bug."
I used both "cuties" to take out, slow down 2 DD's. And while re-loading the aft tubes, it showed I was re-loading those "cuties." Normal reload time is what, 30-45 miutes. I reloaded those "cuties" in half the time, and when I fired those "fish" I found out they were actually Mk.23's.
It may be a bug, but I like the shorter re-load time.