I finally decided to buy used 5D, it costed 350$ and keep my 70D...i can wait for 5DMk (IV?) forever now.
My alternative choices were : 5D MKIII (sell 70D) or keep 70D+5DMKII - As much as i hate "akimbo" camera style having two cameras hanging on my shoulders and hitting ground/surroundings with my lens hoods, i thought this is gonna be better option than single 5d MK III.
1Ds mk II is probably best camera for money, but it´s very rare to get one here these days... :/
Comparing 5D to 5D mk II/70D :
In my eyes, 5D mk II can´t deliver much more than older 5D except higher MPx count + video/live view/MFA/>3200ISO.
i never shoot SOOC jpeg, so better jpg algorithms in higher ISO levels in newer bodies are not important to me. Actually RAW files looks very similar (comparing 5D, mkII, 5DmkIII, 1Ds mk II or 70D)
Noise levels are not on my issue list, but i noticed that certain lenses are not sharp as they should be (24-70L f/2.8 is awful on crop bodies for example, but excels on FF, on other hand 70-200L f/2.8 is amazing on every single EOS body i have tried this lens so far)
5D has horrible screen - old tech, but that´s something i can live with, i just need the screen for brief check of histogram and overall composition. For comparison I like the swivel screen on 70D for different reasons (touch screen with dual AF focusing works really great), not just for display sharpness or vivid colors.
5D doesn´t have MFA feature or sensor cleaning - my current lens setup I use works great on any camera without any tweaking. But lack of MFA could be a deal-breaker for some people with lenses, which require some tuning.
Sensor cleaning is not working as good as i thought anyway... I would really like to hear your opinions about this feature, i find this quite disappointing. Dust is still an issue nowdays:/ Maybe i switch lenses in dusty environments too often....
No liveview on 5D : very useful feature on 5D mk II or any modern DSLR... one of my biggest arguments not to get 5D mk III and wait for IV - I really like dual AF performance on 70D and i hope they implement this feature in 5D mk IV. for landscape or macro liveview is just great.
Same AF system 5D vs 5Dmk II... actually biggest downside of 5D mk II and 5D for me - i can´t track subjects using other AF points than center one. Good reason for me to keep 70D or get 5Dmk III for more action oriented shots. I´am not center point/recompose shooter, I mostly use manual selection of AF points in AI Servo mode.
5D or 5D mk II is huge letdown in this aspect and it is necessary to use center point only in most scenarios.
Auto ISO feature is nice addition to 5DmkII, i use it sometimes on 70D, but it certainly works best on 1DX with metering system linked to AF points and EC compensation on Manual... Without these options, I personally say it can´t be used properly. I really hope 5D mkIV will come with these features as well.
5D doesn´t have current ISO level visible in viewfinder... annoying...
5D has wonderful image rendering, it really makes 24-70 f/2.8 shine or any fast prime. AF center point is certainly usable even with AI Servo in dimmer-light. The price is also very acceptable, i can get almost 3x working 5Dc for price of one 5DmkII!...
No issues using ISO 3200 RAWs on 5Dc at all, SOOC jpegs are very bad though, so if you need great High ISO SOOC jpegs, buy 6D or 5DmkIII instead.
Hope this short review helps someone get right camera!