So far I've only tried a 901. I'm happy with it except for some battery quirks, but I'm mostly just curious to try something different. I'm thinking of getting a penstyle. Is there a difference between PureSmoker's and ElectronicCigaretteSales's? If so, what is the difference? I've been VERY happy with Cash's customer service and products, but the other site has free shipping. Or is there something else besides a penstyle that you think should be my next purchase?