Should I use the yeast cake?

I posted this as a reply on the Richard's pumpkin ale thread, but I didn't get any replies. So I'm bumping it by putting it here.

I'm going to be brewing Richards pupmkin ale this weekend. I ordered the Safale us-56 yeast like the recipe says. I have an ordinary bitter that I will be transferring to keg that was made with Wyeast London ESB 1968. From the descriptions that I have gathered about the two, the London ESB is a bit fruitier and the Safale is a bit cleaner.

Should I just stick to the recipe or throw it on to the yeast cake? I should get a nice quick fermentation that way. Just don't want the flavor to be drastically different.

I'm just wondering what some of you would do.

I'd go with the fresh us-56. Dry yeast tends to boom pretty fast anyway, and you'll want a nice clean fermenting yeast, like US 56, so that the pumpkin flavor can come across un-inhibited.

I would stick with the US-05 (formerly 56), it will attenuate better, I don't think you want to leave the pumpkin ale with too much sweetness. If the ESB is coming out of primary you could always wash the yeast and save it for later.