Is it best to use DVD-R's and burn as slow as possible?
 

The title says it all.

Thanks in advance.

It's best to use DVD+R and bit set it to DVD-ROM. Slower is better up to a point. I use 8x for archiving and 16x if I don't care. Never had a problem yet, but I use a good burner and good media.

+R & -R each appear to have their fans (as do brands X, Y & Z of burner, and brands P, Q & R of blank media)
I always use -R (probably 2000 or more in the last three years? - I would need to go over the records to check...)
I was getting returns from customers until I reduced the burn speed to 4x. I still burn at full speed for my own backups etc. But 4x seemed to be the "sweet spot" for me.
So for me, the only thing that I believe is crucial is to burn slow for maximum compatibility.
HTH

Yup....that is the best method I've found...
8x Taiyo Yuden +Rs with bit setting enabled and burned at 4x or 6x...

Bob T.