In ye olden days, I would finish reading a thread and hit the back back button. I would be taken back to the point in the list where I left off. Now, with the new version, I am taken back to the top of the list.
Shift-click is an ogsend. (It opens what you clicked on in a new browser window) I use it all the time. It probably saves the hamsters some trouble too as they don’t have to re-load the page you were on.
Opening more windows gives your own personal hampsters a little more of a workout, but only a tiny one, and they were probably bored anyway. The SDMB’s hampsters don’t even know how many windows you have open, much less care.