Rehydrate dry yeast?

I have been told by a few very successful members of my brew club Not to rehydrate yeast when making Cider. However, I can't get a straight answer as to why...other than: You simply don't need to...

The several batches I have made fermented fine just pouring in dry. Thoughts/suggestions?

I've never rehydrated dry yeast, and never had any problems with fermentation.

If you're making a low strength cider, the juice is basically just water, with a little bit of sugar in it. So the yeast should rehydrate similarly to an all-water rehydration. The time that I would worry about rehydrating yeast was if I were making a very high sugar cider, like 1.100+, because the osmotic pressure would stress out the yeast.

But, whenever I make a beer that big I make a large starter, so that's never been an issue. I've never tried to make a cider that big.

I think that it depends on the yeast. Many yeasts don't necessarily need to be rehydrated. There are a few out there that give both options of rehydrating and just adding the dry yeast to fermentation vessel.
I agree with Nateo that there's a possibility of watering it down, or perhaps potential sanitation issues due to using multiple vessels, extra work and so on.
There's also the advantage to rehydrating since many items/books/posts talk about yeast absorbing the water, being able to rehydrate without getting any unnecessary gunk in them before their walls are up allowing them to be stronger or somesuch. (Which is exactly what Nateo said about osmoitic pressure).
I've been doing both and haven't seen too much a difference with anything of mine so far, but then I haven't done any real high gravity liquids... except once on accident.

I figure the yeast manufacturers know their products pretty well, I just follow the rehydration directions on the pkg, never had any problems. Regards, GF.

The problem I have always heard is that if you stir in a pinch of yeast in 5 or 6 gal, it takes a long time for them to swim around and reproduce. What I do to combat this is to scatter the yeast on top and alow to float. After 20 min, when it starts to foam, I break it up a little. After another 20 min, I break it up again. I do this several times before giving it a good mix. It just basically keeps them close together until they have established a larger quanity.

they reproduce primarily by asexual budding- don't require any other yeast nearby

Thats good to know dinnerstick. Thanks.

I think I may have found why it's all confusing.

Whether or not they reproduce through asexual budding depends on the favorability of surrounding conditions: when times are good, yeast clones are produced by budding. In times of environmental stress, yeasts produce spores which are capable of withstanding periods of environmental hardship—perhaps even to lie dormant, until conditions improve and the mingling of genes can take place with the spore of another yeast.
http://science.jrank.org/pages/7438/Yeast-Life-cycle.html#ixzz17cytZ3iq