At first glance, it seems like a neat little way to keep notes for meetings, either putting them there in advance of or after the meeting. However, it is more than that. Meshin Recall adds the missing piece in making Evernote your organizer. Without calendar functions, Evernote is merely a place to dump notes. You could annotate your notes by date and subject; but, it's messy unless you're a stickler for consistency in annotating.
What is not obvious, at first glance, is that once you create a note attached to your calendar item, you can add To Do items to that date's note. You can add images, files, tables, audio notes, and all the wonderful things Evernote allows you to do.
Yes, Google Calendar currently allows you to attach documents and files to your appointments. But, there is no checklist option. There is no connection to Skitch. And, that right there is another powerful feature. You can take a picture and annotate it on the same note.
If you have other Evernote Trunk apps on your device, then Evernote acts as the bridge amongst all these apps. When you structure your notes by appointment, it makes it so much easier to go back and pull up notes for an event.
Of course, all is not roses.
There is no indication in your Google Calendar that there is an Evernote note attached. This means that you are limited to using your mobile device or Evernote client to look for notes. It would be nice if Meshin added a link to the individual Evernote item so you can pull it up on your browser or client. But, this is not a deal breaker. Theoretically, if you are relying on Meshin Recall, you are the mobile sort anyway.
In terms of improvements, adding contact information would make the MeshinRecall/Evernote combination even better, creating a sort of CRM.