Spanish Tinto de Verano vs. Sangria

Today I learned there is a summer drink served in Spain similar to the much-touted SANGRIA called Tinto de Verano or Tinto Verano.  Curious, I found a recipe and will create this delight before I leave for Spain in a couple of weeks --- just to compare, you understand ~  This concoction is to Sangria as near-beer is to Beer.  Less alcohol.... Guess I may just work my way from this to that soon.....

1 (750 ml) bottle red wine (a cheap tempranillo works great, or any medium bodied red)
2 liters lime flavored seltzer water
2 cups sugar 
4 slices oranges (to garnish) 

Directions:
1 Fill 16 oz. glass about 1/3 of the way with wine. 
2 Mix in 1 tbsp sugar into wine. 
3 Add a few cubes ice. 
4 Top off with seltzer and mix. Taste. 
5 It may require more sugar, but add it slowly because there's a fine line between bitter and overly sweet when it comes to this drink. Add bit by bit, mixing and tasting as you go, until you have a refreshing summer drink.
6 Garnish with an orange slice.