When comparing Texts vs MWeb, the Slant community recommends MWeb for most people. In the question“What are the best Markdown editors for OS X?” MWeb is ranked 14th while Texts is ranked 16th.
Ranked in these QuestionsQuestion Ranking
Pro Supports multiple Markdown dialects
Unfortunately, this is a global setting for save (it can open any dialect)
Pro Immediate Markdown rendering and preview
Texts immediately renders the formatted Markdown as you are typing it inside the text box. It's quite similar to a WYSIWYG editor.
Pro Imports and exports many formats
HTML, Word, TeX, PDF, ePUB, OPML.
Pro Works on Mac OS X and Windows
Pro Excellent support of LaTeX equations
Pro Small but powerful
It has file tree, can post article, can upload pictures, can render in pretty preview themes, and is small and fast.
Pro Supports publishing to popular web platforms
MWeb can publish Markdown files to various web platforms including (but not limited to) Wordpress, Metaweblog, Evernote, Blogger and Tumblr.
Pro Syntax highlighting in fenced code blocks
MWeb has syntax highlighting for some popular programming languages inside fenced code blocks.
Pro Supports publishing a static blog on FTP
Possible to manage your self-hosted static blog with your own css
Pro There's a free version, Mweb lite, on Mac OS and iOS
Pro Supports both its own database and external folders
So you can have a side project stored on its database, and your current notes on external folder, with simple files, that could be share with other apps.
Pro Drag & drop or paste photos to the editor and display
Supports adding pictures to a Markdown file either through drag-and-drop or by pasting it.
Con Overwrites standard Markdown
Editing a preexisting Markdown document overwrites standard markup in it (for example, interpreting headings marked with leading "#"s and rewriting them with a trailing underscore line), adds extra blank lines between all paragraphs, and adds extra spaces at the head of unordered-list items.
Con Spell checking is not activated by default
There's a built-in spell checker which is not activated by default and is quite hidden.
Con Limited choice of built-in themes
You can download the CSS for these themes and create your own, but would be nice to have more flavors (e.g. GitHub)
Con No word count in older versions
Word count is present in Texts 0.21, at least.
Con No free version
MWeb costs $14.99 and is available on the Mac App Store. There's a free trial available but it's only for 14 days which may not be enough to make a good evaluation of the software before buying.