Do App Tabs and Tab Groups maintain an active connection with the websites they represent?

Question

I really like the concept behind App Tabs and Tab Groups. I have a few questions, though.
1. Will I use more memory opening a new window or creating a tab group with the same number of tabs? I am addicted to Alt+Tab and am frequently frustrated by tabs because I have to use the mouse (I don't use ctrl+1,2,3 because I can rarely remember where a given tab is in the sequence). I see there is a shortcut to access the panorama view, so maybe tab groups will work for me. It really is down to which method uses up more memory.
2. With tab groups, I assume the websites maintain a live connection until you close a tab or a group. This is not like a fancy shortcut, right? Is the same true of App Tabs? We have an unreliable connection speed and I am wary of keeping all my apps connected through potentially long periods of non-use.
At any given time, it is not uncommon for me to have 5 or 6 tabs open (per window), but if I use App Tabs, it could bump me up to 20 or more. Since a handful of my "apps" periodically update (fb, twitter, email, pandora, etc), I'm not sure it makes sense to keep them all active. Any thoughts/suggestions/recommendations on the subject are welcome.
Thanks!
~KJ

Answer 1

With the help of information from user, ptressel, in [https://support.mozilla.org/en-US/questions/1032154#answer-673322 a post here about the existence of sessionstore.js when version 33 was released], I was able to easily recover my tabs and tab groups as follows:
# close Firefox and, perhaps, allow a few seconds (30s?) for any final closing of files;
# check to see if you have a sessionstore.js file in your profile folder, named like the one I documented in my original post above;
# if it is not timestamped prior to the discovery of your problem, open the sessionstore-backups folder;
# check if the recovery.js file is suitably timestamped and, if not, the recovery.bak.
# At this point, you are likely to find that none of them are prior to your problem occuring. If so, open your backups of this folder and go through steps 2-4 to find a file prior to your problem occuring.
# When you find a file, copy it to the root of your current profile folder and name it, "sessionstore.js"
# Open Firefox. Mine opened up as desired.
This is a Windows solution. Sorry I can't comment on other platforms, but I'd bet that as this is just a file copy and renaming, it is likely the same.
For Windows users, you may find you need to sign out and login as an administrator in order to access the backups. You need not logoff your standard account, but do have Firefox closed as described above.
Hope that helps.