Specs are quantitative aspects of the option such as the price
Pros
Pro
Quite natural
Honey bees evolved over millions of years living in hollows in trees; by hollowing out a log you're creating an environment very similar to their natural habitat and thus most likely to fit with the bees' needs (i.e. including any we may not yet be aware of).
If you're keeping bees for honey, rather than simply to keep bees / aid their regeneration, this hive is not for you; the hive is designed solely for bees to live in; so no facility is given to allow honey to be simply extracted.