Note that our Trading Dominion community has now gone back to just using standard Black Scholes modelling though.
This is mainly because:
a) it's a formula that is well known and fully available for analysis, whereas "volatility surface" in ONE and other models in other software are essentially black box closed systems
b) having your backtesting be dependent on a black box model can be problematic, since if the vendor decides to change/update their model then that will screw up all of your backtesting and/or live trades
c) similar to the point above, we get consistency with Black Scholes, whereas with custom models you're at the whim of the vendor getting creative with their model and now affecting your live trades and prior backtests
d) Black Scholes modelling is available on almost every broker and platform, so this allows users to not be forced to purchase custom trading packages in order to obtain custom options modelling