I don't think there is a perfect answer.
Attached boots can't be forgotten and won't come off the suit, but you can kick out of them, even with finkeepers. Attached boots don't have the construction of a good rock boot (no arch support, no ankle support). They make it harder to turn the suit inside out to dry (and if you think you won't have to do that from time to time, you haven't lived with a dry suit for very long
) and heavier to pack if you travel.
Socks and rock boots mean you have boots you can forget. The thick soles on rock boots can force you into a larger sized fin than you want to dive. To keep rock boots or any other kind of shoe securely on the dry suit socks, you have to lace them up well, which can compress the insulation in your sock and result in colder feet. If you don't lace them up securely, you can kick out of them, which is a VERY unpleasant experience. On the other hand, an overboot can have a good, thick sole for rocks, and some ankle support if you're doing entries over rough ground.
Turbosoles (which I am currently using) have some of the advantages and disadvantages of both. They are attached, so you can't forget them. They come with a Velcro strap around the ankle, to make it essentially impossible to kick out of them (and I use finkeepers over them as well). They are soft and the neoprene affords some insulation. The soles are not much protection from rocks (and I'm a little dubious about their durability) and there is no ankle support. They aren't easy to turn inside out, although it's possible. I've also heard they are prone to leaks with time, although I've not had any yet (they've been on the suit since August).
Each strategy has its pluses and minuses. If I were diving where I was doing a lot of entries over sharp rocks (like Hawaii's lava) I'd use rock boots. But I wouldn't use them where losing a fin is a big deal (like in caves). If I were doing mostly boat diving or sand entries, I'd use the Turbosoles.