I can't imagine corrected grain leather having 'grades'...
So long as the price is reasonable for what you are getting...
I apologize for being the cause of the "Great Bata Debate". It started due to my recommendation for the Ambassador series (the ones with stitched construction and full leather soles) on my fb page.
From Shoeshine Uncle's POV, top grain leather actually can be shined beautifully but it lacks of the imperfections of full grain leather which give the shoes character.
To my knowledge, there are different types (not grades) of non full grain leather.
- top grain leather
the texture varies from the amount of sanding and buffing done, the designer brand shoes like to use very smooth leather which look somewhat like patent leather. The Bata ambassadors belong to this category.
- corrected grain leather
a pattern is applied onto the leather, most commonly seen is the pebble grain, commonly seen on very casual shoes like boat shoes, loafers.
- patent leather
plastic coated leather high gloss, used for very formal evening shoes, ladies shoes and handbags, military dress shoes. very easy to scratch very hard to buff away.
Having said all these, even top grain leather shoes have various means of construction, the worse is gluing the upper to the sole, thus a certain "bespoke" shoemaker earning its infamy in the forums.