We had a similar discussion down the pub after a seminar (some present were Yondan) and we basically agreed that being able to handle yourself had nothing to do with Aikido. It's about your background, where your from, if you got out on the town a lot, basically how many scraps you'd had and you'd seen!!! I reckon if you want to use aikido on the street I think you have to be 150% committed to using only Aikido and be very good at it. Half/Half (some aiki, some scrapping) will get you killed IMO. 150% scrapping could save you as well. Serious (well trained) Atemi is another option.