if you are talking about the bottled/canned variety ,It's quite popular amongst some of the young here.
In my search I found I mayor who wanted it banned from his town and another person asking why on earth it was allowed to be called beer.
I couldn't find the carbs but the ingredients suggest its high in carbs, I also found it on a list of the sweetest beers with a score of 8/10, (for comparison Fosters was 7/10
I've posted the ingredients, I won't translate as it seems fairly obvious
Desparado
Bière-sucre-arôme (75% de Tequila)-acidifiant : acide citrique- antioxydant : acide ascorbique.
. Saveur très sucrée. C'est une bière agréable, pétillante, et dans laquelle se retrouve une pointe de Tequila. Alcool : 5,9%
Desperado Red (this one has decided to pretend to be healthy by containing vitamin C and saying that its low GI :!:
Bière, sucre, concentré de jus de fruits rouges, extrait de guarana (contient de la caféine), arômes : 50% de tequila, 25% de cachaça), acidifiant : acide citrique, antioxydant : acide ascorbique, alcool : 5.9% vol. Contient du malt d'orge
Taux Alcool : 5.9%
Bière riche en vitamine B,C et PP
Riche également en glucides lents provennant de l'orge et qui libèrent progressivement leur énergie dans l'organisme