I just finished a top down for my great niece in 4 days!!!
Naturally I would like to experience that quickness for myself.

I just finished a cabled sweater for myself where the seams aren't completely invisible.
Seems top down would be the cure there too.

Are there any pitfalls doing top down cables I should know about before mapping it out?

Nope, most cables look the same from the top or from the bottom, so you shouldn't have any problems.

I don't have any experience with unusual cables top down. Sue, do you do them exactly as they are written or do you do them from the top of the chart down? or anything different? I did one simple C4F upside down and did it exactly as given and it worked. I was a bit surprised.

They work just the same way, and with many cable patterns they look the same way upside down as rightside up. I don't do cables much, but most of them will work okay.

I was thinking the only one you'd have to flip that I can think of is the deer antler ones.

Of course me being a hunter might have to use that one.

You know you could knit it without changes... no one would know which way it's supposed to be and when you looked down while wearing the sweater, you'd see it the right way.

I would know :)

How about the jog you get at the join when making stripes in the round?

Should I line up the join with a purl background row that goes top to bottom?

(I'm making my first rough sketch and thought of this. I'll be making a not so rough sketch after I get a ribbed sweater far enough to divide the arms off.)

Do a search for 'jogless' join, there may be an entry at Techkntter's blog. (http://techknitting.blogspot.com)