Excellent.

Removes the burden of a long-running browser: it's always as if started anew, regardless of how many tabs you have. Only the few recently-visited tabs are loaded and running, and all of the others got unloaded (just like a freshly started browser would have them). Really nice for machines without a ton of free RAM.

Useful, simple to use, high performance gain, and open-source. Highly recommended!

Environmental friendly addon

Love it, one of my must have add-ons.

Not actually that useful. Storing Tabs in RAM may be faster on your Machine.

It depends on your bottleneck, do you have 4GB of RAM, use that Addon.

Do you have a slow Wifi card and processor, dont use it, as sites reload more often.

Really useful extension, nothing to really complain about.
Simple, Light, Effective! I use it all the time

halved FF memory usage.

C'est dommage mais le module plante. De temps en temps, au lieu de "réactiver" un onglet mis en veille auparavant, il le supprime complètement et firefox affiche une page vide.
Il est alors impossible de retrouver l'onglet et de savoir ce qu'il y avait à la place de cette page vide.

I suspect this extension is what's been slowing down Firefox for me and using a lot of my PC's memory to the point of severe lag - it's my only recent add-on and disabling it seems to have helped so far (fingers crossed). Good idea but the slow-down is very significant after a while for me at least.