Some customer reviews revolve entirely around the fact that 5 episodes are missing. It's a damn shame and it's fine to point this out, but it's not helpful when you trash the whole series because of this. If you want to rant, feel free to add to this discussion!
The reviews are supposed to review the product not the series, If we compare like for like, the Season 3 box has 23 episodes and costs £13, this box contains 13 episodes and costs £16. That is not value for money, so the product should get poor reviews because of it.