I have to say, this has become a very good thread for me. Thank you, especially, to Mr. Mead and Mr. Modesto. I think it is an important issue to discuss how O-sensei's practice of aikido has or has not been reproduced, be it in terms of technique, spirituality, or conditioning.
That being said... I'm leaning toward Don's point of view on this one.
O-sensei's technique is social practice, and while it could be seen as a map, it need not automatically be seen that way, let alone what the map is specifically a representation of, or what it 'calls' us to do. The author (assumably O-sensei) cannot guarantee the correct reading of his texts without the use of very specific disciplining techniques, and the amount of variation and change within aikido over the last 60-70 years suggests that if the purpose of aikido was to create a spiritual vehicle that reproduced O-sensei's spirituality, then aikido has not been successful. Looking just at uchi-deshis, one cannot say that Shioda, Tohei, Sunadomari, Saito, Chiba, Saotome, or Kanai (to name just a very few) all have the same spirituality. The spirituality of aikido, and how it should inform aikido, are incredibly contested categories.
If one wishes to develop spirituality through aikido, I think this is a very possible endeavor, and also a very good one. However, it requires more than just the technique of aikido. The practice of aikido goes much farther than that. It includes an understanding of Budo, a structure to dojo organization (sensei, sempai/kohai relationships, amount of intensity allowed when and why, etc.). As such, I think some relatively stable organizations have developed some relatively standard ideas on spirituality/philosophy for their respective aikido practices. Simply knowing the right way to do move & do technique is not enough, as one needs a context to give those things meaning.
Because aikido practice is not homogenized by any means, the forms of spirituality it produces (or fails to) are legion.