The one caveat that needs to be addressed before I go into detail is that this extension is probably best for the following users: 1. People who have a decent understanding of styling if you want to make it one of a kind. This can be said for ANY large gallery component, most of which (e.g. Phoca, JoomGallery, etc.) terribly ugly styling out of the box. 2. People who want to integrate their gallery w/ JomSocial, Kunena, or Community Builder.
If you meet these two criteria, then this component is second to none.
The uploading is fast and flawless. It is handled automatically based upon the user's browser compatibility. It will use Google Gears, HTML5, or Flash. You can also batch import by zipping a whole directory of images, and uploading to FTP (which, is SIGNIFICANTLY faster than just dragging those files and having them upload individually, as FTP is suited for larger/fewer files)
The back-end is much simpler than other galleries.
Nested Categories, many sorting options, category access restrictions, upload restrictions, etc.
Picture management is great. The structure is similar to Phoca/Joom, but the image previews are shown onmouseover, which makes for a more pleasing management IMO. Thumbnails, and different image sizes are generated seamlessly without you ever knowing, and there is never corruption or memory errors. This in stark contrast to Joom/Phoca. Pictures can be sorted in many ways: by category, # of hits, # of downloads, rating, order, date, status, price, etc.
Fantastic and simple integrated comment system! Comments can be managed via the backend easily.
Ability to vote on images, save them a favorites, download them at full resolution, edit (for uploader/admin). All of this is customizable.
Original images can be protected by .htaccess (good for people who aren't familiar w/ this). Can be downloaded w/ watermark, or can be sold.
Built in sales! I haven't tested this functionality, but I will soon be deploying this on a client's site (it's 95% finished), but even the fact that it exists is a big plus. Options like this usually have to custom built or at least custom adapted.
Several useful modules included. Ultimate module allows many display options. The new slideshow module is not living up to its potential, but it has a lot of promise.
Active development. This component is being actively developed. New versions and features seem to be added at an impressive rate.
Competitively priced. For the site I am implementing this on, I originally tried SimGallery. While SimGallery is great code, it doesn't have many of the features that I needed, especially the ability of users to upload into a series of set categories. SimGallery is basically a knock-off of Facebook's photo sharing. Albums have no categorization nor the ability to do so. SG is also NOT GPL in any way. It's ionCubed, which is a pain (it's also why you don't see it on joomla.org). So it does less, it's more restrictive and it costs more.
The new (1.9) templating system is a big addition. Although I developed a custom template before this upgrade, I wish I hadn't. This update changed many of the elements, separated all the core elements into a base CSS, and broke off all the main styling attributes to a separate stylesheet. This is a better use of styling, but more importantly, it allows for much easier creation of custom themes.
The claim that this component cannot be styled is demonstrably false, and I can only assume that the user who posted this simply does not possess the knowledge to do so. I created a fully custom dark/semi-transparent theme for every aspect of this component in about a day.
Now some cons.
First, most of it is table-based. This is not divergent from other galleries, and the reasons are obvious. Dealing w/ positioning things like a large custom grid of pictures and text is very challenging w/ div-based setups, especially if it has to be dynamically controlled. I don't take off points for this.
A really stellar component should have a class or id on nearly every element, and this component leaves a number of them out. The solution is to wade through the PHP and add your own element ids/classes to allow for better styling control. Some things use inline styling, which, obviously is not good practice.
On the comments page there is built-in functionality to click on the image-submitter's name/avatar and go to their Kunena (via backend setting) or JomSocial (default) profile. Strangely, although there is a nice CB plugin to show the user's uploads (My Gallery tab), there is no built-in functionality for it to link to the user's CB profile from Datso Gallery. This effectively makes Datso a one-way street w/ CB. You can get from a user's profile to their images, and then to datso, but you can't browse datso, and get to the CB profile.
I am in the process of modifying/coding this, but it should be a built-in function, without a doubt.
The only thing SimGallery has on Datso is Ajax. The Datso experience, especially on the details page, would be stunningly seamless with the addition of ajax browsing.
The slideshow module that was just release is poor. There are plenty of models out there to build a slideshow on, and I can only assume that this (being just released) is in a budding stage of development.
In summary, this gallery has a ton to offer, and the polish and feature-set continues to grow. I have deep experience w/ many galleries, and this one is by far the best for a social experience.