I personally perfer iron sights myself. Mainly because Ive used them for so long on real firearms, it only comes natural to me in the airsoft world as well. The uses of optics for me is only with my really high power stuff, like .375 H&H mag.
Also, For the most part, Im always afraid that if I drop a rifle with a scope or a red dot on it, it may nock it off zero. For the most part, iron sights have a better chance against this.