Atlantic/Atlas Cedar repot in autumn/fall

[Shibui]

Would you say they are good material to work on? if so what sort of styles are you think about?

Cedars make stunning bonsai but don't be fooled into thinking you can develop a great Cedar bonsai quick.
As previously mentioned, slower than many other species to grow. Also very slow to set into position. It might take 2-4 years before your bent over cedar actually stays bent when you take the wire off.
Great promise but extremely frustrating is my take on Cedrus as bonsai.
If you decide to take one or more on, I'd advise have a few other quicker species an the go as well so at least you'll get some satisfaction while your cedar grows.

 

[WNC Bonsai]

I agree with Shibu on taking a set. I have some branches that have set in the last year but they were fairly fast growing, thin, young ones. I asked David (from the YouTube video) about his experience and he said it takes a minimum of 1 year for trunk bends to set. I still have the wire on mine after a year and plan to leave it there until next spring. BTW another good YouTube source on these is Madam Bonsai but be aware she is in Melbourne Australia and has a very mild climate so take what she says about growth rates, pruning, and root work/repotting with a grain of salt.