I heard that the Arcsaber 10 has a 'soft leather grip'. Is it worth putting an overgrip over it, or would the original grip tear up my hands and give me blisters?
how about searching for the answer? its really convenient! like looking here! I have heard similar sentiments to the post i linked to. A lot of people say it feels good, but that it is probably better to put an over grip over it. try it for yourself. do what you like, because they aren't the ones playing with your racket.
The only reason why any badminton grip would tear your hands is because it's too small for you and it rubs in your palm when you hit.
Although it's by far the best fitted grip Yonex have ever provided, it still doesn't compare for me to a properly wrapped (i.e. slightly wavy) Karakal PU Super. I played half of last night with the fitted grip and switched to a yellow Karakal for the second half - the difference in tack was astronomical. I'd say the Arc grip has a very good surface texture (similar to a Karakal Peachy), but it's too smooth and doesn't have enough give for me.