DoF really seems like the current way to go for early survival at higher difficulty levels. My biggest issue with it atm though is it pretty much obliterates warmongering games. Sure I can try and get as many DoFs out so I can have a peaceful NC+HE or NC+REX opener and get a decent LS push...but if I attack any of my friends, I am bound to being unable to do any viable trade for hundreds of turns to come.
I finally managed to get a good diety game rolling after toying with DoFs. I had a single DoW on me in early game from Greece accross the map. Bribed friends to DoW him and bought peace ~50 turns later. Blew about 1000g on that but it was well worth it.
I kept spending to bribe wars between my various friends (even at the cost of one telling me not to be friends with another) in order to slow their expansion and tech progress from building so many units. Also because I have not had any unit until my 2 early allied CSs (both combat CSs) started to provide me units.
Ghandi kept taking a tech lead over my 4 city setup (played as france to avoid having to build monuments and save those precious early hammers). Luckily, playing in such peaceful lands with 2 combat CSs granted me about 14 units, mostly swordsman and crossbowmens. Seeing as Ghandi was in line for both a science AND a cultural victory before I could win science, I power-upgraded my units to the french legion (UU - infantry) for a very late game war. I had had mongolia-babylon-america bribed to attack Ghandi 10-15 turns before I could bubble the infantry tech.
I tried denouncing ghandi 2-3 turns before I would DoW praying it would reduce the impact of the war on my other relations (for further trades/RAs and just because I'm going for science and not for domination). Poped infantry tech through a GS at turn 175, spent 3 turns upgrading units, DoWed on turn 180. Went straight to his capital since he was my immediate neighbor and it was open. Took it by turn 187, on turn 190 he offered me 2 of his remaining 3 cities and some spare change for peace
.
After suffering 18 turns of ******ed unhappiness and -50GPT, cities were back to production and I'm techlead @ turn 210 with 2 GS lying around and 4 or 5 RAs that I had to pay the era advance for :s.
What's going to be hard now is that war put me at Guarded with 3 civs that I was friendly with before and babylon just won't renew a DoF. They are #2 in techs and I am affraid they might DoW on me. Sure they are friendly, but they also have an even-teched army that's 3 times the size of mine. Hopefully the stolen Hejmi castle from Ghandi will help me survive if my nightmare occurs!