I will say that if you never pushed the BIC very hard, there is not reason to think the VTF-2 will sound very different at nominal volume levels. The only difference would be the extension, and that is only if the content actually has very deep bass extension in it. Also keep in mind it is very difficult to hear deep bass at soft or moderate loudness levels. It is at higher output levels that the VTF-2 would differentiate itself, presuming the BIC is a competently built subwoofer.
Saving Private Ryan is not a movie with a lot of deep bass. If I recall right, most of the bass lay above 30 Hz.
If you want to see the difference deeper extension makes, try this: play the 'pods rising' scene in War of the Worlds, starting at the point the alien machine starts coming out of the street, but switch between the VTF-2's operating modes during the scene to hear the difference. Start the scene with both ports open and operating mode switch set to 'EQ2' with the Q control at 0.3. Now during the scene, plug a port, set the operating mode switch to 'EQ1' and Q control to 0.7. War of the Worlds has deep enough bass that the difference in deep frequency extension should be audible.
You can switch modes between scenes, but if you are cranking the movie hard, be sure not to run the VTF-2 with both ports open and the operating mode switch set to 'EQ1' because the driver will not be properly safeguarded in that condition. Every other combination of operating mode configurations is safe, just don't run two ports open on EQ1.
If you want to see the difference in dynamic range that the VTF-2 has over the BIC, set it to two ports open on EQ2 and blast a tune that has tons of bass. Any of the tunes in
this thread will fit that bill. Don't be afraid to crank the VTF-2 HARD, it can take it.