It never really bothered me. G3 are the ponies I loved the most as a wee lad. And the ones I am most familiar with (as well as the ones I love the absolute most.) So I got rather used to the idea of just having one symbol. I always thought of it as a condensed upgrade. In exchange for having more detail, colors and what-have-you they had to condenses two symbols on both sides into one. Don't get me wrong I adore G1 too, but G3 symbols just have so much more charm to them, and they just POP with color. Same with their mini symbols in the eyes, I love that!
as for the cutie-mark VS symbol debate I honestly bounce between the two of them when i type/talk but I prefer Symbol. I thought 'cutie-mark' was stupid, but just a wee bit cute in G3 because it was hardly ever mentioned. just a cute little word on the box. G4 beat the word into the ground. now it just sounds cheesy. When I was younger I just said "Tush-mark" or "Butt-brand"