I was ranked in Aikido way back right when I first started BJJ about 10 years ago. I actually think it is martial arts on the highest level - which means you have to be flawless at it to make it work. I do use some aikido concepts and wrist locks now as a 2 stripe brown. For me Aikido was my entrance into grappling and finding Roy Dean helped me transitoin to BJJ and Judo instead of continuing on.
One day before Aikido class a big tattooed guy, with much more Aikido experience, who is a good friend now asked me if I was feeling "scrappy" and asked me if I wanted to spar. That kind of thing doesn't happen much in Aikido. I replied that I am always feeling scrappy, so we squared up. I had previously trained in a bunch of standup arts and it was the first time I sparred without strikes. At this point in my martial arts education I had been pouring over Roy Dean's blue belt DVD. Like obsessing over it as we didn't have a BJJ school that was easily accessible. In about 30 seconds after feeling eachother out a bit i ducked under his arm , crawled his back to RNC and he fell back and tapped. He was as surprised as I was and wanted an immediate redo. We square of again and this time we tangle up and i get a body lock to a trip. I end up in mount and he text book pushes up and me and is armbarred instantly. Again, we are both a little shocked. That was pretty much the last time I went to Aikido. I persued BJJ full on after that. Trained under Roy and even had an affiliate school under him for a while.
My advice would be that Aikido is not worth the time to explore if you are young enough and want effectiveness. My Aikido does help me but not in a way that I have some huge advantage over other brown belts. I consider it more as part of the path that led me to my true passion. I may return to AIkido and then Tai Chi when I am ancient though.