Hi Robert, thank you very much - that really means a lot, especially coming from yourself. I love Ian Gillan too so if I sound anything like him then I'll gladly take that as a compliment!
Training with Four Pillars has been really beneficial, it's an amazing programme. I have mainly used it by working through as many of the Vocalize Demonstrations (which I have on my iPod) as time will allow. I probably now need to use it in a more organized way as your book directs, but I have been doing the Foundation Building Routine at the beginning a lot, and it has really helped a lot in opening up my range and finding head voice properly.
I am certainly interested in any updates, or if you have advice as to which specific exercises from Pillars that might be the most beneficial in helping build strength and stamina in a more 'belty' configuration in that higher part of the range (particularly between the G4 and C5), for the Dio/Gillan/Dickinson powerful sound. I find that at the moment I can find it for a while but my stamina and/or strength needs working on somewhat.
Thank you again Robert, I really appreciate your comments.