RATTI  I tried Curio a bit and found that does too much for me. It is confusing; also I found the MindMap part weak. For it's price you could buy Mindnode Pro and NoteBook and a lot of other software. Try out what fits you best.  
(Version 6.3)

DINGDONGDADDY  This program works flawlessly, has a thousand features, and for the life of me, I can't figure out what to do with it. I know the answer is "it will be what ever you want it to be," but since I don't know what I want it to be, I don't know how to use it. Wish I did because it looks great and works great.  
(Version 6.1)

JUST A USER  I did pay for the update, I think it is fair to pay for something that really does work and what a developer actually spent some time, thinking and energy on.

Curio is feature-rich software that can be used for a great deal of different stuff and I had no major bug issues so far.

The indvidual sub-functions, like mind-mapping, are not as feature rich as in dedicated software, but that is not to be expected either. They DO work great as is and DO have all the important import and export options.

Hope that program will be going strong for a long time!  
(Version 6.0.1)

KORM  If the new features are worth the upgrade fee, pay it. If not, don't pay it.  
(Version 6.0.1)

SUNBURN  OK, so here we go again. Looking back, we have:

7/2007, upgrade from 3 to 4: $39

8/2008, upgrade from 4 to 5: $39

And look, it's September 2009, and here's Zengobi, hat in hand, asking for another chunk of change. (I'm academic, so at least my upgrade fee is fairly modest, but I believe the non-academic upgrade fee is $70.)

IMO, this is a really bad business model: punish your most loyal customers by hitting them up every year. Each new version has had some nice features, but not enough to justify the level of cost. If this was even every other year, I'd be OK with it. But annually? A little excessive, no?

I don't even use Curio all that much, though for the things I do use it for, I can't imagine what else I'd use to do it. But at this rate, I'm going to start looking pretty seriously. I'll probably cave because generally Zengobi does a good job of keeping up on OS updates and I'll probably be missing some cool Snow Leopard only feature when 6.1 or 6.2 comes out... but maybe I'll just skip this one and wait until 10.2010 and go for version 7.

It's a nice program--version 5, I mean, I haven't shelled out yet for version 6--but if you go for it, you're going to have to think of it like an expensive subscription service rather than a single purchase, because that's clearly the developer's model.  
(Version 6.0.1)

XPLICIT  Dear Curio Developer(s),

"CMD " is for switching the application's windows. It's a default, pre-set shortcut. You shouldn't assign another command.  
(Version 6.0)

ROGER KATZ  CAUTION - MacUpdate in NOT up-to-date at 7PM 19 Jan '09. The MacUpdate links do NOT give the Curio 5.4.1 versions. I used the MacUpdate links, and was only able to download Curio Standard 5.3.1 and Curio Pro 5.40. Nevertheless, I was able to successfully get the 5.4.1 versions directly from the developer's website.  
(Version 5.4.1)

N2ITV42  Can't say enough about this program - does it all for the creative professional. The price does seem high at first, but you get over that once it becomes a staple of your workflow  
(Version 5.3)

MAR6473  I've been using Curio for a couple of months now. Once you start using it you realize what a unique program it is. I looked at it before but the price turned me off right away. $149 seems like a lot when I was already using another note taking app that cost $35 for collecting info and managing research projects. Beyond being able to collect a lot of information and organize it, it lets you spread it out, move it around, interconnect it, etc... It's sort of like being able to spread all your bits of info out onto a big table to get a good look at everything. The mind mapping feature does everything I need and is great for organizing your information (There are other mind mapping apps that have more features than Curio. You just have to try it to see if it does everything you want. For me, there is a lot of strength in Curio's ability to do a bunch of thing within one document). Omnioutliner and Omnigraffle are fantastic programs but I can do everything I used to do in both of them in Curio. The developers are very responsive which has reassured my confidence in the app. For project organization, research, and collecting information on a given subject, it does everything I need. If you need advanced word processing tools, you can embed Word or Pages documents into your Curio project. They give you an extended 60 day trial so it gives you enough time to really try it out. If you just want to mind map, there are apps that just do that, if you just want something to dump bits of info into to collect over time, Journler is great. But, for general project and research management with a lot of flexibility that really helps you get organized, Curio really stands out.   
(Version 5.1)

TECHWRITER  I think the important thing to look at here is the magnitude of the upgrades. Version 5 is really bristling with new, compelling features. Curio is turning into a virtual 'control centre' for my day-to-day work. It's open all the time, both in the office and at home, so the value of the product for me is far, far beyond a measly $70 per year. If the next version adds as many major improvements as the last one, another $70 will be a bargain.  
(Version 5.1)