It's my understanding that the concepts of hard (external) and soft (internal) are related to ki, and not to what the technique looks like.
The clearest example of hard technique is karate. The opposite is tai chi chuan. The difference is that karate emphasizes a hard body, that is, the fist must be hardened, and the muscle and bone must be strenghtened.
In tai chi, smooth, continuous breathing is emphasized. The concept is the opposit of karate in that in tai chi, the body is strengthened from the inside out; that is, the nervous, skeletal and cirulatory system, the internal organs, the deep, inner muscles, the external muscles, and even the skin. Admittedly, this takes a longer time to learn. This is why for military and law enforement purposes, hard forms are often taught. This even includes hard forms of aikido.
If one wants quick results, one can practice a hard style of aikido. But if one wants to learn aikido as it was meant to be used, then breathing, hara, posture, relaxation, and the extension of ki should be emphasized in every phase of the training.