Sure there are differences. No two arts are the same - not two schools of aikido are the same, btw.
I dropped out of aikido for reasons that didn't really have to do with the actual training - and I was devastated. But after a while, I noticed that what I had wanted in aikido also was to be found elsewhere - that "good aikido" really equals "good jujutsu".
Oh, I liked Chris Li's answer! And it's not like it's gonna stop me from adding my own.
Ok, I have aproximately 1/3 of a lifetime in total to practise Aikido and I feel the style of traditional Aikido I practise suits me just fine, I tried other aikido styles that didn´t suit me even I feel there are many things that various Aikido lineages have in common.
We have people crosstraining in the dojo but in my personal perspective this is less desireable because it takes a lifetime to master one art..so plenty of room for learning in my perspective.