Hi man!
I'm using the stock ones which come with the kit. Only replaced them about a month or so, and damn they are worn out. They still work, but can feel some kind of "transition" when i brake, as compared to brand new ones.
How are your running habits like? I run about 8 batteries a week on average, on 23T stockers and 14x2 mods. And they still wear bloody fast!
If the lightweight ones can handle the stress, guess I'll get them... my car's overweight still @ 1.6kg, last I checked