I like the above combo.
I'm fine with Beta (which is indeed as intense as they make it) and Gamma (which seems fair enough except for the frequency part ...dunno how they measured that and what factors they think it could depend on, sounds voodoo). What they describe as Delta playfulness and giggling is rather annoying ...but the NFs I know seemed rather "abysmal" and passionate, strangely enough. Alpha seems too soft.