No problem, I look forward to the next book when and if it comes out. (Version 6?, I'm sure soon) I used to do the Host fails N+1 or 2 method. Then after reading the 4.1 then 5.0 books, I realized the disadvantages of doing that. I do the calculations for all my designs and then again when I visit a client site.
I too tend to shy away from resource reservations as I'm very sparing with it only on critical VMs. If too much reservations configured, it can cause issues with over commitment if and when a failure occurs. I see some admins go out of control on reservations and I see potential disasters. Talk about memory ballooning!