X230 Slice battery- Worth it?

Can get x230 slice battery for like only $30 , was wondering if it's worth it?
About how many extra hours can you really expect from it if anyone has got one already?
I get roughly ~5hours from a brand new 6cell of real usage (even some of the online tests says you can get 9hours from it, which I obviously don't believe now)

Also does it adds much weigh and bulk to it? I currently Really like the size of my x230 not sure If it would be better if it were 2x thicker.
Thanks.

 

Perhaps a better question would be how much battery life do you need? The slice is a six-cell, so I'd expect twice the battery life if both are new. I recall getting about six hours on the six-cell battery of my X220 while it was new. The X230 review unit I had was slightly better if memory serves me correctly.

I believe the slice is just over a pound and half. Coupled with a X230 and six-cell battery, you'd be right around five pounds.

 

Just got the battery, and I wouldn't recommend it to anyone, It's SUPER large and Heavy, It makes the whole laptop 2x thicker and almost 2x heavier as well,
It was such a nice size portable laptop before.. Not even sure Im going to be using it
Not worth the extra weight to be honest, should have just went for extra 9cell swappable battery if it were cheaper...