I think the reason why KSG looked better with Surbhi, is because of the bonding that they had. If your offscreen bonding is strong with each other then it shows up onscreen. You can clearly tell the difference, from then and now.
As much as I prefer KSG with Surbhi (due to the chem they created), i feel, to see such a chemistry be build back again with her and Raquesh, needs time.
They both basically build the show together, as the show went on, so did their bonding, and then finally they chem. it all looked and felt natural, because of how the story got created and formed, over time.
However, when Raquesh came in, his and Surbhi i mean.. Zoya and Asad's chem was already made and created, he was just stepping in the same shoe, Asad had worn so, it would be unfair to expect the same kind of chem created with Surbhi and KSG, with Raquesh and Surbhi, this early.
I feel, let time go by, plus, Raquesh is doing fab.. however, I feel, it would be best or better for him if he didn't try so hard to focus on how Asad acted and reacted before... but would be best if he just acted as her his acting and gave better light to the character of Asad.
I understand, he has to live up to how Asad was and has been created by KSG and its a tough job.. however.. if he just followed his natural self when acting, as he acts.. then it would look a lot more better.. than look like.. 'he is actually acting' or trying hard to fit in. just my 2 cents :)
but.. all the best to both of them! Surbhi and Raquesh! :)