Bottling question

I'm brewing my first batch right now, a brown ale. Last weekend I transferred it to the secondary fermenter (a glass carboy) from the first fermenter (a plastic bucket). I've mostly been using this website as a guide
http://www.brewsupply.com/HowTo/firstbatch.html

The website recommends that right before bottling, I ought to rack the beer back into the sanitized plastic bucket before adding the priming sugar. This seems to me to be unnecessary. Is there a good reason I shouldn't just add the priming sugar to the beer in the secondary fermenter, mix it up a bit and then bottle?

Thanks in advance!

Take a look at this thread: https://www.homebrewtalk.com/showthread.php?t=5174

If you just add priming sugar to the carboy it's in now, and mix it up, you will also mix up the sediment that has settled to the bottom of the carboy. It would be much better to put the sugar in another bucket and rack the beer on top of that. That will server two purposes. It will mix the priming sugar well, and will get the beer off the sediment.

you want to rack it again to get it off the trub in the secondary. helps for clearing the beer. also you need to add the priming sugar before you rack. then when you transfer it the beer gets mixed up with the priming sugar without becoming overly oxidized.

Does your plastic bucket have a spigot on the bottom? If so, you definitely want to put the priming sugar in the bucket and then rack on top of it. This way, as others have mentioned, the sugar will mix more evenly with the beer. Additionally, bottling from a spigot on a bucket is much easier than from a glass carboy. No need to deal with siphons.....gravity is your friend

OK, thanks for the advice, you've convinced me to rack back to the bucket before bottling. There's not a lot of visible sediment in secondary fermenter, but still I guess eliminating every little bit will help. Plus, evenly mixing in the sugar is important, I gather. My bucket doesn't have a spigot, but I do have one of those bottling wand thingys that should make bottling a bit easier.

Thanks again for the help and I'll let you know how it turns out!