I gave it three stars, so just a passing grade (Or is it "sufficenza"? Bah, I never understood how to spell it) despite having listened, relistened, worn out, and destroyed this CD. Let me be clear, the CD is not bad... it's just that it doesn't flow. Let me explain better, a good CD doesn't have to be made up of only 13 masterpieces; there can be just 4, with the rest being catchy little songs...
In my opinion, what makes a CD great is also its "editing". And in "El Vals Del Obrero" it's done at least by an amateur... Just look at the first three songs, where Ska-P wastes their two best songs on the CD! Namely "El Gato Lopez" and "El Vals Del Obrero"... The choice to start with "El Gato Lopez" is excellent, being a lively, cheerful piece, etc., etc. (Especially when followed by the "sad" "Ñapa Es"), but "El Vals Del Obrero" could have been moved to the 6th/7th position, so after 3 songs you've already heard the best of Ska-P. Not to mention the annoying "Revistas del Corazon" that precedes another masterpiece, "Romero el Madero", so I'll correct myself... in 5 songs you hear 3 masterpieces (In the end, the CD will have 5, in my opinion... for the rest, songs that are so-so). Then the "funeral", two extremely boring songs like "Sectas" and "No Te Pares" that precede the excellent, but lyrically a bit commercial, "Cannabis". Then another three incredibly boring songs, or at least compared to those above, definitely worse (while some remain listenable, if you listen to "El Vals del Obrero" and then "Insecto Urbano", you feel a bit let down). The album closes with "Sexo y Religion", which is also a bit commercial in its lyrics (it heavily targets high school kids with a revolutionary spirit) but catchy and all in all a good SKA song.
Honestly, I would have edited the CD like this: "El Gato Lopez", "Ñapa Es", "Revistas del Corazon", "Sectas", "Romero el Madero", "Insecto Urbano", "No te Pares", "El Vals del Obrero", "La Sesera No Va", "Sexo y Religion", "Animales de Laboratorio", "Cannabis". Besides this personal opinion on the editing, the album presents another flaw present in many Ska-P CDs: Repetitiveness. Indeed, it's difficult in a genre like SKA not to be repetitive, and Ska-P doesn't stray from that stereotype. In the end, the songs all sound alike, making the album decidedly static, besides being "haphazardly edited". It's a pity because there are enough songs to make an excellent album, but it's a shame that the other, filler songs (let's call it the CD's salad) are practically all similar.
One more thing, a point in favor of Ska-P. Pul Pul, the singer, has in this CD perhaps the best voice ever (not of all singers, his best voice ever, to be clear), vitriolic, radiant, explosive, and Pi Pi's first counterpoint is heard and gives an extra boost to this CD, a boost that has allowed Ska-P to become the number 1 SKA group in Europe (And I dare say even in the world), at least for fans. Musically, there's no disputing it, they're very good, from the trumpets to the bass. The only real problem is that perhaps the "genius" is missing, someone like Izzy Stradlin, understood as someone who can write lyrics for vocals, guitar, and all instruments, always creating excellent melodies. Ska-P lacks a composer, although Pul Pul overall always manages to find the right notes with his second guitar. That's it. A good album, without a doubt, maybe a little overrated.