All Fed ships need to be outfitted withe the Phased battle cloak from the TNG episode - where Rikers old captain - now an Adm were working on the experimental cloak in secret and there was a mutiny on the ship.
I fly the defiant as my main ship. I don't think that the Defiant needs a battle cloak. That would probably be overpowered. I do however see a few issues which could use attention:
1. Spam sees through and rips off cloak negating it's purpose. In KvF you might as well not use it as there's usually 1 or 2 carriers.
2. Context windows drop cloak. That makes no sense. I don't remember the Defiant decloaking every time Warf said something to Sisko.
3. The time to cloak is an issue. A battle cloak would be too short of a window (shoot, cloak, rinse, repeat). 10+ seconds to drop red alert is too long. As it stands now, the cloak, which uses a console space, is a bit of a one trick pony. In order to use it more than once during a spawn/lifespan in PvP you need to jet far from the battle and hope no spam is around or following you.
It would be nice to see #1 and 2 fixed. Perhaps there is some middle ground for #3.
Ok than do a PVP match were you go against 10 Klingon ships that all have a cloak and all are either consiting of Fleet Vor'cha's B'rel's and Fleet Quin Heavy Raptors and each of them is getting a +15% to their damage.
I play both sides FED and KDF and the Klingons can overun a FED fleet easily, for the FED's it is much harder.
And now the KDF have access to an Escort with a battle cloak, that is tougher than the C-Store and the Fleet version of the Defiant.