You got it.
Although I believe your data will be split up through all channels you're connected to. A little bit on each channel.
I know D3 helped me a lot, because I wasn't hitting my 15mb during peak times with my old D2 modem. Speeds would drop to 7-8mb during the evening. I upgraded to 30mb with a D3 modem and I get 31 or 32mb all the time now. In my market (Lubbock, TX) we have 8 bonded downstream channels.