[Arelius]

> does not load all the restored session tabs at once either

As someone who always has too many tabs open, I consider this a plus.

I do however think you can disable this in about:config : browser.sessionstore.restore_on_demand

[Zardoz84]

also, if you use Autodiscard plugin, you will find that FF use less RAM and Ru. more faster. Essentially discard and suspend tabs that you aren't using.