Well they are a little bigger than most advent ships, and they might have slightly shorter range, but I wouldn't think they would be that difficult to keep in a battleball. Is there any specific problem you are having with them?

As for uses, there really wasn't one but since the last patch fixed the Illuminator bug they might be a good way to boost your firepower a bit (I personally think the Advent should rely on strikecraft more now but that's just me). They are actually the best heavy cruiser in terms of DPS per fleet supply, though like heavy cruisers as a whole they do not do as much damage per fleet supply as most other ship types. They are pretty resistant to everything but bombers though and can handle pretty much any frigates your opponent sends your way.

You won't be able to use repulse as freely as you would with an illuminator-based fleet, but the Destra hits harder and still benefits from a shield projection/regeneration combo quite nicely.  A few guardians, a Progenitor or two, and a big cluster of destras is actually one of the best ways to steamroll an Orkulus.

Destras are by far the HC with the highest DPS, and their weapons can be upgraded almost as much as phase missles.  throw in a haylcon, and you have some serious brute force.  Will crush preety much anything except bomber spam... and one must be carefull for the pesky support cruisers who will attempt to shut you down (subverters mostly, (duh), but hoshikos, and even dominas (each at 4 supply) can be microed to turn off a 10 supply HC... which is a good use of thier time)

-Total research expense is much higher than an illuminator's.

-If you are going to rush, do not go for Destras. Hopefully that is obvious. Late game, the Destra can easily pump out much more DPS than the other HC with all plasma research and its passive ability.

IDK, ask Darvin.

I usually play as TEC, and I do not go for the Kodiak at all...

Oops sorry,

Syneptitude...