ive seen ppl complaining it scratches their 3ds , it might be cos its a knock off brand.
im planning on getting a hori Duraflexi , is it any good ? i think its a bit rubbery any thoughts
Dust getting trapped inside the case has the potential to scratch the 3DS, I haven't noticed any issues with it on my o3DS XL though. Haven't used one on my small n3DS, since it has replaceable faceplates I figured I don't really need one. Plus, dust could scratch the 3DS whether it's in a case or not, so it's not like a case is worse than no case at all. You would almost certainly get more scratches if you didn't use a case at all.
Edit: Took the crystal case off my o3DS XL and gave it a clean just to check, and as far as I can tell it's still in mint condition, there were some smudges that looked like they could be scratches but they rubbed off. I've also had it in a pouch most of the time, but sometimes brought it loose in my pocket because it's huge with the pouch. It's a limited edition Pokemon X/Y one so I've been really careful with it, and it's had a crystal case on it since almost day 1.
The plastic of the crystal case is pretty soft, so it should be very difficult for it to scratch the 3DS on its own. There are some scratches on the outside of the crystal case, which could potentially have been on my 3DS if I didn't have the case, so if you're worried about the 3DS getting scratched from normal use a crystal case is definitely a good idea.
My crystal case is just a cheap one I got from eBay so any one should do. The inside of it should be completely smooth, at least it is on mine, as unevenness could promote scratches.
I don't have any experience with the Hori Duraflexi, it's not really a crystal case since AFAIK those are all hard plastic, though TPU gel is what I've used on my phones and it's done well. Since it's soft, it should absorb some impact from drops, which a crystal case won't really do (though I still don't suggest dropping it
), the scratch protection should be equal or better than a crystal case and it should be more durable as well.