I guess this all depends on looks right? Or Whether you prefer Physical or Special attack- those stats are the only difference between 'em. Erureido (How do you pronounce that?) is neat and I'm glad that little-boy-ralts doesn't have to fear turning into a lady, but a man. I do, however, still prefer Gardevior and I probably always will. I used her to wipe out Wallace in the Elite Four in Emerald. She kicked his, and all his water pokemon's butt!
Although, this thing, Erureido, can get Bulk Up, putting a stop to its weak defense and he's got a pretty impressive Physical Movepool. They'd both make great battlers, so I guess I just pick Gardy because she's closer to my heart.