Re: High(er) Intensity Weapons
I believe a core component of competent aikido to be a competition of success. Raising the level of intensity is a constructive solution to creating a competitive situation. In another post I also mentioned increasing the severity in which we execute technique; while tangental, I believe you can also increase the level of competition by increasing the severity in which we execute technique.
Somewhere along the way, aikido lost the ability to see competition as a constructive process. For me, it is an instructional encounter if my partner attacks me more correctly than I perform technique. In such an encounter I should not be able to perform technique and my partner's obligation is to illustrate that fact. Again, I think this critical feedback from more intense training would apply pressure to under-performers to either shape-up or ship out. Also, I think somewhere along the way aikido is losing its ability to critically correct itself. Ushiro Sensei has commented that aikido unequivocally needs to improve its ukewaza, the singularly best tool of correction in training.
As to the specifics of intense (and correct) sword work in aikido... I remember an AJ article with Kuriowa Sensei. At a Hombu meeting, Kuriowa Sensei politely observed that the Aikikai should no longer perform public weapons demos because the sword work was offensive to real sword people. Instead of saying, "this is unaccessible, bring good sword people to the dojo and get our instructors trained to do proper sword work", the Aikikai no longer includes weapons work in its curriculum. There are instructors on individual levels who did exactly that - went out and found good sword people to learn how to make their aikiken better.
All this said... I enjoy more intense training when it gives me the opportunity to evaluate my skills and illustrate those areas insufficient to function on a higher level of engagement. One of the things I enjoyed at the seminar was that George Sensei made comments about improving our ukewaza. When I work our with a senior, I want to attack and train up to his level. I do not want to attack poorly so that senior has to train down to my level.
Going back and fixing your aikido after such training sucks, but that it the constant hammering that works out the impurities in training. This type of training is not for everyone. There are many people who neither want the increased physical activity nor the critical feedback. The seminar Phi was talking about is an intensive that is limited in attendance - 80 people are not going to that type of seminar. If a good kendo person can whip you, get better (realizing that sometimes our martial paradigms are in conflict). If a good karate person is punching your lights out, move better.