Just got through the 60-70 content and I thought I'd post here how it was without RDF for all the same reasons given in my original post; For point of accuracy I arrived in OL at 59 and just left it at almost 69 to quest in Northrend. It helped a lot that I started adding everyone I could to my friends list when I was level 30 and even though not even half of those players are regular at leveling or have even logged on for several days now it still helped me a lot to form groups. I highly suggest that to anyone who wants to run dungeons consistently.
Still though I found my self 3 and 4 manning Hellfire Ramparts and Blood Furnace]. Nothing new as to the reason why, people simply don't want to run a dungeon(s) without quests and those specific dungeons have only a few quests between them, some of which require quest chains to unlock. Reason for that being the exp isn't worth the effort and the dungeon loot is out leveled quickly as once again I had several players tell me they were "busy questing". I managed to form a group for Underbog and Slavepens, a full 5man and it was great because I haven't ran those since WotLK retail and of course Warmane sticks to the blizz-like theme as best they can even with this low level content, in this case it was near flawless. On that note though, there was an incident in Sethekk Halls with a non-working quest, I recall it being broken when the server launched. That's one of the biggest reasons players run the Auchenendoun (idk if I'm spelling that right) dungeons, because the quests are actually right at the entrance; that being said I managed to run 2/4 to completion and they were well done, a reckless tank wiped us several times due to the NPC CC which is something an inexperienced tank should look out for in TBC dungeons. These were the last of the TBC dungeons I found groups for though, even the higher level group quests I couldn't find groups for but that's not so surprising since we unlock NR gear at 67-68.
I asked Global about the state of NR dungeons and if I would be able to rely on them heavily to level 70-80, I was told the first few dungeons aren't run often but you can find groups for them. Obviously the higher level we get the better the group forming will get so I'm looking forward to consistent dungeon runs 76+.