This is simply annoying.
I have a Parcel Line feature class set up with subtypes (preparing for future migration to a Parcel Fabric). The default is set to Parcel Boundary (most common used), but when I edit, modify or split one of the subtypes the lines change to the default Parcel Boundary. This creates an extra step to have to go back and change the lines attribute type back to what it was previously.
I find I spend more time working around how buggy editing is, then actually getting any editing accomplished.