Thanks! Glad you liked it!
I think I give you everything you need to know about the monetary system in this video:
I don't think it makes sense to say "the value of a vest." "Vesting" is how Dan chose to refer to Steem Power as far as an investing category. Steem Dollars are liquid because you can exchange them for Steem today. Steem Power is "vesting" because you cannot exchange them for Steem today. The value of a unit of Steem Power (a vest) will be whatever the market price of Steem is based on when you decide to power down and the pay out schedule (I believe each weekly pay out is based on that current price of Steem). As I say in this video, I believe that the productivity of the population combined with the growth of the population will outpace the growth of the Steem money supply which means that there will continue to be greater demand for the currency than supply. This should mean that the price of steem will go up over time, and so cashing out your SP in the future will always net you more money than if you cash it out in the present. However, predicting the future is impossible and this discussion is only relevant to removing your capital from the Steem Economy. If you do not see the long term benefit of the ecosystem then that means that you believe that the price of steem will go down over time and so you should cash out as soon as you can. If you believe that the Steem monetary system, steemit, and any products and services that will be built on top of Steem will create tremendous value in the future, then you should keep your capital where it earns the most interest: in Steem Power. It really is that simple. Hope that helps! :)