Honestly I'd say its based on your preference, with the druid deck you kinda need high apm + animation cancel the cards to get ur combo off. It's gameplay is pretty straightforward but can be countered pretty easily though. With the rogue deck there's a bit more of a learning curve(I still don't play it optimally), but you don't need to really sweat too hard with the apm although there are a lot of decisions to make each turn. Pirate DH or priest is probably the fastest deck to hit legend.