I ask the the same question you think Euro 2 is a Turbo or something. [are you living under the ROCK] 
Its for controling hazardious emission from exhaust which makes the O-zone Layer weak.
@friend just to in increase your knowledge "euro 2 technology" means the mechine secrifices its actual horse power. So the regular 125 can kill her easily since its non Euro 2.
RX115 is a far-cry for you. A good CG 125 can tare apart your 125 Delux.
No hard feeling performance wise this mechine is not better than
the regular 125, tough is comfortable and sporty looking put there is nothing like sports performance in it.
This is not only me all the real Lovers of Honda 125 knows this.
Deluxe is only good for the Papu Fellows (H)