Canon 24-70 2.8 or Canon 28-70 2.8

Can you kindly let me know which one is better, I know the issues that Canon 24-70 is having and I have to return mine as well. What is the quality of canon 28-70 2.8 and is it much sharper than Canon 24-70?

Just one thing to keep in mind regarding the 28-70 2.8L is that is is no longer serviceable by Canon since it has been discontinued long ago (there's a thread around here from yesterday, I believe, discussing this).

28-70mm and 24-70mm. According to them they would recommend the 28-70mm over the 24-70. When I had to make a similar decision as you I ended up with the 28-70mm and I never regretted it, the only reason I sold it was because I wanted something faster and ended up with primes. But do note that Canon does not service the 28-70mm any longer, the service cutoff was late last year.