One significant difference between Monero and Dash is that in Dash a significant amount of the "circulating" supply is actually tied up in the masternode network, around 55%, ~4000 masternodes, at the present moment. This can support the price when the price is rising or stable but can also lead to sharp crashes if for example the price drops at a greater rate than the masternode net reward. These masternode coins cannot be used in commerce. With Monero on the other hand all of the circulating supply is actually circulating.