One of the things about ModX is that it's over-reliance on inline Snippet tags to generate content using a tag based structure and manually typed parameters, leaving a snippet prone to typo errors (eg. typing parameters wrongly). This is because Snippets are convenient to create, and many addon developers rely on these a lot.
Why not have metatagged/commented variables in a Snippet with some information on the variable type and possible values, allowing a standard ModX GUI to be hooked into every snippet? That way, a GUI could easily be plugged into the snippet system, allowing more user friendly drag-and-drop into post-box kind of functionality. Parameters like 'docid', 'parents',etc. could use a common GUI to select from existing ModX resources. It's amazing that after all these years, people are still using primitive tag declarations and hand-coding the parameters manually within an HTML/Content document (without type-checking!), and for snippets with lots of parameters, you get a long string of parameter-dependant text!. I understand that having such a manually-typed-text system allows for flexibility, but if you adopted a metatag scanning system for Snippets (maybe even var documentation, though that might bloat snippet size so an external http link would be more reasonable for such a case), you still get flexibility, and manual text edits could be a last fallback, perhaps a type-hinting IDE would be great. Likewise, Chunks should have a "Rollover it" to check what it outputs, rather than having to refer to the Chunks folder and wonder if anyone mistyped the chunk name. Why can't there be broken links reported for chunks/snippets/snippet parameters too? Why can't ModX resolve such links? Additionally, if certain parameters are no longer used in later versions of Snippets, the metavar tracking GUI system can give warnings on unused/redundant parameters within a Snippet tag. (eg. browsing a site while logged in developer/admin in a special mode could give warnings of pages with broken snippet/chunk links).
I find that Wordpress (bad example) has more user-friendly on-board plug-n-play features for generating common things like menus, galleries and such. Not so with ModX, which requires linking chunks with snippet declarations, and manually checking that your parameters are correct within a snippet call. Changing a chunk name doesn't resolve any snippet parameter that may rely on that chunk by that name, without any form of binding between them. Thus, Modx can appear more 'backward', even if it's deemed more 'flexible'.
Wordpress (bad example) has a sidebar on the left for users that immediately want a "click to start application" kind of approach (Mac). Modx doesn't, and assumes end-user admins are smart enough to navigate a folder structure, click on relavant parts, right-click and perform actions an experienced user should, following the system's "convention" (Windows Explorer/Windows Shortcuts/DOS).
Good thing about Modx (in particular, Revolution) is that it has good built-in output filter capability to handle most use cases. Though at times, one may wish to simply just have PHP and hack their way in cases where Modx output filtering doesn't seem sufficient enough, very seldom this is the case. Modx is a great tool for designers that don't know much PHP (or developers that don't want to over-modify a designer's HTML design, especially if it might change later), and don't mind taking time to learn a tag-based structur that works great, providing a standardized, cleaner and far more dynamic content approach compared to writing templates with PHP codes found in Joomla and Wordpress. Besides, if one needs to write PHP, it's available in a non-monolithic snippet call, so everything is much more cleaner allowing for multiple solutions to a given problem.
