Great idea, awaiting more robust implementation

I was so intrigued by this, as a potentially useful tool to add to my responsive design workflow, that I bought it on impulse. I dont necessarily regret it, but there are some features Id love to see added to make it live up to my hopes.

In its current form, I wonder if having two viewports glued together, with little else, competes with two different browser windows open side by side and loaded with various 3rd party extensions.

- It would be great if there were preset sizes that could be quickly and easily set for each of the two viewports. For example, there are a number of "Resize Browser" extensions on the market that let you select from a drop down of preset sizes (and set custom sizes as well), and it will change the browser window to those dimensions. So, if there were presets like iPad portrait, iPad landscape, Nexus 7 portait etc. iPhone portrait seems to be the default for the mobile size, would be great to get other portrait presets and maybe even landscape too.

- A bandwidth simulator for each viewport would be pretty cool as well, allowing you to preview the mobile side at 3G speed compared to desktop side at Broadband and such

- Being able to export the current side-by-side screen views to a Bitmap (PNG) might also be a handy shortcut to having to screen grab manually

Anyhow, I look forward to possible updates in the future, thanks for your consideration.

J.Y. about Duo