Great idea, I'd go 4 stars maybe 5 except it's cripple-ware Rated 3 out of 5 stars
Cripple-ware. Until you purchase it, it throws a nag screen about every fourth time you try to move to another site or open another tab, splashes a screen up saying "Gee, wouldn't it be great if this annoying hassle screen quit popping up? Well hey, all you need do is buy this software and it'll be all better." Okay, it doesn't say that, but it should, it would be accurate. Also crippled is the anonymous mail -- only works when you upgrade. And the history, which is encrypted on their servers -- I'm glad it's encrypted. But hey, I'd rather delete the history, how come I can't? Oh, I see -- I have to purchase the software.
One of the (very many) things I love about Firefox and Mozilla is that pretty much everything is free, as in beer. This is the first piece of software I've come across that's crippled and I've been using Firefox a long, long time.
Which isn't to say that I don't support great software, and the people who write it -- I do. I have given money for LastPass, for AdBlock Plus, for Session Buddy (on Chrome), I dunno, a number of others. I toss Wikipedia a few bucks when they ask. I give EFF a few bucks a month. I'm one of the 23 people who actually paid $30 in 1990s dollars to support Netscape when Micro$oft was burying them.
And I bought this software. It just goes against the prevailing winds that I'm forced to do so to get all the functionality.
But, I bought it. I bought it to support them, because this is an excellent idea and a pretty good implementation of it. Because though I've wanted to set up TOR I don't have the technical chops to do so, and this is easy--peasy, put an add-on onto Firefox. I bought it because I know that I want it -- already it's what I use for banking and I'm going to bring any $$ type things into Cocoon. It plays well with LastPass, a must for me. I purchased it because I want to be able to deep-six my history, or at least have that option.
It does slow Firefox down, but not terribly, and sometimes not at all. (I use both Chrome and Opera, too, and they are both blazing fast, so that's part of it, being used to Chromes speed.) On my machine, a search on google works great, but google images I get the thumbnails on the search page but when I open the images in another tab, I go to that tab and it's empty. Bing images works fine. Dudkduckgo works fine; I know I don't need it if I'm in Cocoon but I checked, just to see. Cocoon doesn't choke when I open a lot of tabs, which I tend toward; that said, I've got 8gig of ram on this puter and I suspect that helps with lots of tabs open.
It works great with the latest Firefox, seamless. It's pretty, if that matters to you, blue on the tabs bars. I'm on a laptop, thus limited screen real estate, I'm not quite sure (yet) how to hide that tool-bar yet keep it's functionality, but I think I read on Lifehacker that there is a way to do that.
It's got some rough edges -- I cannot open a different tab from history IE when I go into history, find the page I'd been on, I cannot right click or double-click or anything else to get that to open in another tab, it only goes from the history directly to the page.
Only once have I not connected to their server, it timed out. But I tried again and got in so that is just life.
It's definitely worth having, I somehow missed it when everyone was writing about it last year and only just found out about it a few weeks ago. I read pretty much all I could find online, then came over here and got it and it's great, overall it's great. If you're interested enough in it to make it to this page, likely it'd be worth it to you to purchase -- I know I would have -- I just doesn't like being forced to, maybe it doesn't matter to you.
3 stars, would have loved to go more.