It’s great that illustrator can edit PDF files and it’s great that Illustrator can save out un-editable PDFs. But why, for the love of sanity, would I EVER want to save an un-editable PDF but then have the original, currently open AI file vanish leaving only that useless little PDF file? I would ALWAYS want the original AI file to remain the main current working file. But it doesn't.
Or if, for some reason I can’t fathom, this behaviour is necessary and right, then at the very least it should display in no uncertain terms that I'm currently editing an un-editable PDF, and strongly suggest to me that I might want to save out an editable PDF or an AI file, or even do it automatically, before I close the file (or Illustrator crashes, as it is wont to do).
Say I'm working on an AI file and I need to save out a small un-editable WIP file for the client to view. I go for File-save as -> PDF/smallest file size/ untick ‘Preserve Illustrator editing capabilities’. I send off the PDF file to the client and carry on working and saving, assuming I’m working on the original. The file looks and behaves exactly as it did before I saved it so intuitively I assume it is the same, original AI file, with the PDF file as a copy. However, when I come back the following morning having closed the file, only the low resolution un-editable PDF file remains. The file is useless, and I have to re-do all the work from all the way back to the previous time I saved the file before I saved the PDF.
Much annoyance, hair loss, time wasted, face palms, etc.
The thing is, I now /know/ it does this, and I go out of my way to avoid it happening but, in the rush to finish work and send stuff to the client, and handling multiple versions of files, it still happens. Now clearly this is my fault but damn, Illustrator could behave a lot more helpfully in this regard!