Looking at the Device Simulator Page @ Radioshack it looks like the Evo 3D will only have 1.01GB of space for apps (like the Sensation.)
Look Here:
Device Simulator Care
Go to: Setup & Go --> Perform a Master Reset and Click Next to Step 4 and see the space available for 'Internal Storage'
Look Here:
Device Simulator Care
Go to: Setup & Go --> Perform a Master Reset and Click Next to Step 4 and see the space available for 'Internal Storage'