Aikido's grappling moves may go against the principles of striking styles, because they leave the practitioner exposed to getting hit; but they may present a more graceful way to drop an opponent to the ground, rather than punching him in the face as a strike-based style might do.
In the first video above, see Steven Segal demonstrating some Aikido moves.
In the other two videos, see Sensei (Master) Kevin Christie from the NIA Aikido Club demonstrating some typical Aikido moves.
I've trained a bit at Birmingham City Centre's NIA Aikido Club, and it's not bad. Consider joining their classes if you're interested in Aikido and don't mind following the traditional formalities.
Visit the NIA Aikido Club website: niaaikidobirmingham.org
Since I joined the Birmingham NIA Aikido Club some months ago, I've done some rolls (similar to what I've done before in Ninjutsu) and some punches (similar to what I've done before in Karate). But mostly it's been about wrist-grab defence. Attacker grabs Defender, then Defender does one of a dozen moves to put Attacker into an arm lock and often falling down to the floor. I guess at a more advanced level, there will be practice for defending from punches and other moves as you see in the videos above.
I try to keep an open mind, because most of the techniques in Aikido seem effective, but most of these moves go against the key principles of Wing Chun Kung Fu. The aikido techniques involve a lot of movement which would be advised against, in Wing Chun, for leaving you exposed to being punched or counter-trapped, and at the level of Wing Chun that I'm used to practicing, this is a very big mistake.
But Wing Chun is mostly about striking & blocking, and maybe it's less aggressive to do an arm-lock & throw? Maybe Aikido's advanced grappling moves share the same considerations as Wing Chun, while sacrificing some defense in order to tame the counter-attack to a less dangerous level? If so, then Aikido may be just as good as Wing Chun, and a good way for a master striker to develop some new skills.
Ai Ki Do refers to the solid style (ai), the fluid style (ki) and empty style (do). In this way, Aikido represents levels 2, 1 and 0 of the ancient levels of fighting.