dracon/sybarite. are they worth it?

So is there ever a time when it is worth it to take a dracon or sybarite?

Not really. The only time I would, would be to grant LD9 to a large blob of twenty warriors, otherwise I just don't see it being worth while.

there is something to say to 5 blasters in a squad... sadly that one is overpriced and only 6" range... so no. In 20 warriors though like Mush said it would be nice to have LD9 and a close combat weapon other than say... the duke who you are most likely putting in there

In a word, no.
If, for some reason, you want an archon/trueborn close combat unit, then yes, they make sense, but they are a bad choice for a worse one

One thing I'm a bit confused on, those are considered characters correct? The book says something like (and I don't have it here so forgive me) the space marine sergeant upgrade is then a character ... and then it also states that characters (not just ICs) have precision strike/shot. I know that is a very, very minor thing and likely not worth the points cost of an upgrade but having that advantage is something to consider when taking those upgrades ... unless of course I'm wrong in them being considered characters. I'd love clarification if I am wrong or right either way...

they are, but if you're warriors or trueborn are in hand-to-hand with anything but the weakest combatants, that's not going to save you.

Part of it is wishful thinking. Do you ever want your kabalites in melee? No? Then why assume they'll end up there?

They are characters, so precision shot is a thing, but most people don't think that giving a Sybarite a Splinter Cannon is kosher.

Mostly Sybarites make alright challenge monkies or leadership buffs to large squads as has been mentioned above.

I think an argument can be made for the Dracon as a clean-up character. That is, as a character meant to assault into squads of 2-3 marines. Possibly with an offbeat choice like shredderborn.