I've just received yet another replacement for my Hero3+ Black. It's from the latest batch (H3B+B081) which GoPro claim has the focus/sharpness issue resolved. Yet, testing it against my old Hero3 shows little improvement! Despite being informed by GoPro that the Hero3+ offers better sharpness which it doesn't.
Very disappointing.

Chris,

Are you comparing it with your old Hero3, or your returned Hero3+?

I was about to buy a Hero3+ until these problems surfaced, so I went with a Hero3 just in case. I would love a Hero3+ black or silver if the focus issue was resolved, as my uses would be for slightly further away things than a "cool selfie of myself on a surfboard".

I'm not cool enough for that.

Comparing it with my old Hero 3. Good things about the 3+ are much better white balance & more powerful & faster wi-fi. Sharpness wise they are the same, at least on my cameras.

I bought a hero 3+ silver recently! and have used it at a couple of weddings and two school productions, with no sign of focus issues. Others seem to be having problems though and there are a couple of DIY repairs on the net that can sort it. One involves levering off the lens retaining clips from outside the camera, rotating the lens a couple of mm and putting the the rings back, seems very simple. GoPro Hero 3+ Infinity Focus Mod - Fix Your Hero3+ Focus! - YouTube

Roger