Ah! So this is YOUR site, CoachEric! Congratulations!
This website appears to be very polished, and it's endorsed by Dave Butler so you can't get much better than that!

I think there's room for multiple good PV sites on the internet, but I worry about the
http://www.m640.com site being ignored due to its subscription business model ($9.95/mo). This might be a killer - financially out of reach to most PV students.
Both Dave Butler (Art of the PV) and Roman Botcharnikov (m640) are esteemed coaches that follow the Petrov Model (the 640 Model being an enhancement to the Petrov Model), and any serious student of the vault should read ALL of the information published by BOTH of these coaches.
And CoachEric is building a good reputation on PVP and with his athletes.
I haven't read all of the Art of the Pole Vault site yet, but it appears to be free, and the content is nicely laid out.
Kirk Bryde