Shihonage is one of my favorite techniques. While beginners (myself included) might have trouble realizing the effectiveness of techniques, at least remember how good the training is for everyday non-martial situations. If you concentrate on the concepts of entering, blending, and diffusing, you might be able to talk and finesse your way out of many potential martial situations. That's the most important thing about practicing aikido.
When aikido must be used in a martial situation, I think it could be highly effective if you know the techniques and remember the fundamentals.