Hi there, I strongly recommend you check out my Basic Guide to Space PvP, stickied in the PVP forum. It is written from a Federation player's perspective, but can apply to both sides for the most part.
Yeah, since I got bored with my fed (max cap, did everything, ran out of content, blah blah) and been playing a klink, I gotta say, a lot of feds just kinda don't belong in pvp. They EASILY get the tools to screw over klinks. Pug against pug, I'd say feds'll win most of the time unless someone takes charge klink-side fast. In a premade vs. premade setup, I might put my money on the klinks, but only by a nose. And even then I'm not sure.
Except tier 1. If you're playing tier 1, oh god no, feds don't stand a chance. The miranda is so much garbage. Gets much better for you after that though, so just avoid space until tier 2.
As for ground they have the exact same tools, so uh, yeah, that one's your fault.
I have not seen that it is unwinnable. I only tried PvP a coupe of times since I hate the queue system (sp?). But my side (Feds) held our own...I will say that those Klingons can sure lay a hurting on the unprepared though! If you like challenge, then PvP is the way to go!