I prefer O-rings with the attachment on the spine, which is what my entire collection from 1887-2016 is in (1887 are reprints. of course). Starting in 2017, I reluctantly gave in to the D-rings with the attachment on the back because that's all Wal-mart seems to have these days. When you pull a binder, more care seems to be required for the D-rings with attachment on the back. I've had them slip out of my hand with pages flying everywhere. I'm just more careful with them now.
Also, there are times that some of these cheap binders don't seal completely, so I'll wrap a little scotch tape around the center ring if this happens.