Glenn,
I too just received my SD1+ with AJ's EXP modification installed. I met with AJ at the Winter NAMM show and Ketron's US distributors allowed me to take one of the two SD's being shown back to my store. I've been playing with the new sounds and styles for a few days now and I couldn't agree with you more. If I would have put my review into words, they would have been almost exactly as you stated.
I do believe, for those who already have an SD1+ with the auto load feature enabled, the New Grand Piano is the same new samples as AJ's comes with. The new Rhodes pianos and electric and acoustic guitars are a major improvement in achieving a similar sound to what Yamaha calls Mega Voices with multiple samples at different velocity levels. Ketron will now be installing and selling SD1+EXP's here in the USA. If anyone is in the Los Angeles area and wants to try one out, it's available at my store.
George Kaye
Kaye's Music Scene
Reseda, California