I'm now torn between the 24 f/1.4 II and the 24-70 II.
From what i gather (online) there is little or no difference in IQ at f/2.8 or higher.... so it really breaks down to a choice between a speed vs versatility (assuming equal-ish IQ, excluding barrel distortion which is higher in the zoom; vignetting appears to be about the same in both at equal aperture)...
Is that statement true or am I forgetting a particular perk of one over the other?
How often will i need faster than 2.8 in a wide-angle vs how much i would like better IQ over a range! dang... I feel like Homer Simpson choosing between glaze and sprinkles!
Unfortunately, renting is not an option...
If I remember correctly, you are based in India (same as I am). IMHO, shooting in this busy country requires large apertures because blurring out the background is usually more than desirable. If you do want the background, you can always step the lens down. The reverse is not possible unless you have sufficient time for PP.
I was generally advised (here) that the 24-70 II obviates the need of primes - maybe true for some users but for what I shoot and in the conditions I shoot, I really can do with a wider aperture. While I do like the 24-70 II, I do regret the fact in a number of circumstances, that I can't shoot a 35mm shot at f/1.4.
Choosing between these two lenses is extremely difficult because both are stellar lenses. You need to identify how you like your shots and whether you are willing to change lenses on the go. I went for the zoom because that felt like the best decision to take at the time - Going forward, I will add a few primes though.
PS: Do you intend to buy the lens in India?