I didn't start aikido for self-defence reasons (I wanted to do weapon work). But I really got into the unarmed stuff. Its also come in handy many times as a practical self-defence. It is much more useful for stopping fights as often people will try to push/grab/hold you before working themselves up for a fight. It is not so good for the situation where you stand opposite each other in poses and are trying to damage the other person. It is much more about instinctive reaction to a swing or stab.
Techniques are often grabs etc from the start, but the idea is to 'blend' with the attack (our club actually start from overheard strikes as it emphasises this blending as more important than fixed 'technique'). Although there is some practical benefit early on, I think this is only the same benefit you would get from ju-jitsu. It takes a couple of years before you start to get beyond technique and are more able to blend effectively with an attack.
Like many martial arts the training obviously depends on your instructor. If your instructor is not teaching it as a martial art for self-defence (at least as a major aspect) I would recommend that you do not try and train there to improve it as a self-defence.
Also, don't consider kick-boxing as something seperate from aikido. Aikido is a set of 'principles' of body movement, rather than a set of techniques (the techniques you can get from ju-jitsu; probably a lot more in fact). These same principles of blending and ki can be applied to kick-boxing as well (and probably are to some extent).