To echo some others. Going with a master template that holds all modules is the way to go. While at SAP I reached out to knak looking for a mailchimp like editor based on modules. We eventually decided with having their consulting side: Revenue Pulse, build out an editor 2.0 template with all the modules - from the master template we could create unlimited derivatives that could be applied to different products etc... but still hold on to the parent brand. There were a couple extra modules that team members needed later on, and Revenue Pulse was able to add them in later. However, it's been a few years now so I would imagine they could recommend a very robust master template with every conceivable module.
Not affiliated to envato or anything. Just thought to share this idea - use a modern drag and drop email builder that supports Marketo and then import the whole HTML. Use Marketo to only send out emails, tracking and such but build the email itself externally. This one is a very good option:
As already written there, all the power of the editor is linked to the quality of the template you are using.
There is still room for improvement, though. Read this: Email editor 2.0 is leaving room for a v2.1
We were also frustrated with Marketo's email builder, mainly because of the specific syntax vs. actual coding and because most of the Marketo templates didn't want to render correctly in Outlook, which is the primary email client of our customers. I happened to come across the Hoosh template builder, which is not code-free, but does give some flexibility in building an initial template.
Yes, we had a template built as well. The modules are very similar to what's available in dreamweaver and it's made our lives much easier to build directly in Marketo. I'm more disappointed with Marketo's form functionality and Landing Pages. Would be great to have built in recaptcha on all forms and an update with the landing page editor.
For now we've moved to Instapage for all landing pages which is much easier to design with and has much sleeker forms to work with.
I was also shocked at the low quality of Marketo's email editor tool. Hopefully enough people chime in on this to get this bumped up the priority list to improve sooner than later.