The Turnigy Ultimate 4600 pack has been really good for me. My only complaint is that they are out of stock in the US warehouses right now. There are some 4200 packs in the HK US. I'm holding out for the 4600 again so I will be able to share it with my B54 in the summer
I won't buy SMC packs any more. I've had to throw out several lightly used 1S 1/12 scale packs that were very puffed.