Thanks for the link.
We prefer selecting our site when we arrive. When still working, we usually would take off a day or two early (nice to have a long weekend anyway). The VA parks are pretty good about accurately describing site length, and from what we have seen there are probably only a very few sites in each campground you wouldn't want.
It would seem that the best of both worlds would be the way that many COE parks (and some other states) with sites set aside for reservations along with some 'walk-in' sites'? If they do go with site specific reservations, sure hope they add good descriptions including exact length, width, and slope and shade info, as well as pictures.
The only park where gate staff have assigned sites (James River) we found the staff really great about accommodating our requests. We had a family get together, and they put all 6 of our campsites together.
That said, the $5 per day per dog fee (up to 3 days) will still keep lots of folks away. Add to that the $5 reservation fee (per stay, even for walk up) and the state park is not cost effective for one night (even with the 10% off for the lifetime park pass).