I have trained with the same sensei for a number of years. He is a great guy (like an uncle to me) and very skilled in what he does. I feel that I have learned a great deal from him and I could still learn a great deal from him.
BUT . . . . . . . . :
*After multiple seminars and visiting other dojo I seriously wonder if our dojo's brand/style/flavor of aikido is congruent to the national org. and hombu. Kihon is WAY different, names of arts differ, attack dynamics are different. Yudansha exams are done by the national org and I worry that I (and others) won't be doing things the way the Shihan or testing committee wants come test time.
*There is another dojo in the same org that is actually a little closer to my home. This dojo has a very respected sensei in the national org. with truly awesome skill. The students at the dojo are very welcoming and always treat me like one of their own. Their "flavor" of aikido is also very congruent with my own personal taste.
You're probably thinking, "This is a no-brainer. This kid ought to go with the closer dojo with the highly respected sensei (and awesome skill)."
The center of my problem is my sense of loyalty to my sensei. He introduced me to aikido, dealt with my s**t for years, and is truly a great guy. I feel I could be considered disloyal by changing sensei and dojo. Heck, I feel somewhat ashamed writing an anonymous post on this topic!
I know that ultimately the decision is mine to make. I was just hoping that a few folks would offer some outside perspective.