THIS!!!All caps is the good one
the all caps is the European/South America version which still uses the original ingredients which allows for the glass to go from hot to cold with no issues.
The lower case version is the american/Canada version which uses a different cheaper formula for the glass. The glass is "stronger" in terms of it taking a hit but it loses the property of going from hot/cold without cracking.
The all cap is more fragile but retains that hot/cold property.