The current beta offered space and ground PvP instances to queue into from the sector map, which is essentially the game's world map where you warp around in real time. PvP can be entered by approaching a planetary system on this map, or simply via a menu on the UI. Unfortunately, I wasn't able to try out the open PvP Warzone maps, although I'm not entirely sure Cryptic has them in for beta testing right now.
Anyhow, after finishing the short-yet-informative tutorial, it's time to warp off into the real stuff. Klingon ships come equipped with disruptor banks that sport a smaller firing arc, making the front of your ship far more deadly than the typical Federation vessel. The trade-off is that you can't circle around enemy ships, doubling up on on a target with front and back weapons arrays, which ultimately offer more laser oomf than a single bank of phasers or distruptors. This is one of many interchangeable parts (indeed, much about ships can be altered as if they were characters all to themselves) but it's a wonderful example of the tactical decisions that need to be made both in and out of combat.
You start off with the Bird of Prey, which is a far more nimble ship that can also cloak in the middle of combat, unlike other warbirds in the Klingon Empire's fleet. This makes it a fairly nasty vessel to mess with, and I had many Federation players cursing me as I employed hit and run tactics on them. Also, because of the BoP's turn radius, it's much easier to evade warp core explosions.
Yes, cloaking is pretty nasty. You can even use full impulse while cloaking, allowing you to zip across the map and claim control points for the Empire -- assuming you don't decloak near any Federation ships. If you do this, it's very bad. You see, shields drop completely when in cloak. I occasionally found myself obliterated by copious volumes of photon torpedoes and mines, which tear through your hull like old school Cookie Monster through homemade chocolate chip cookies. So, for all you worried Feddie players out there, stealth isn't all bubblegum drops and rainbows. It'll probably get even more worrisome when science captains being detecting stealth more easily.
Although, since this is beta, the turn radius on BoPs is potentially subject to change. In my personal opinion, however, this attributed to Klingons kicking serious Feddie butt in PvP. That didn't stop the Federation from winning a few encounters, but overall it felt fairly skewed most of the time. Something to consider here is the fact that Klingon players -- the ones continuing to play -- are going to get very, very good at PvP. It's important to note that since most players were flying low-level ships, much of the overall landscape of PvP has yet to be seen in Star Trek Online.
As for progression through PvP, it's entirely viable for those interested. On the Federation side, equipment rewards are different for PvE vs PvP, but there's plenty to be gained by going out into space and butting heads with Klingons. Thankfully, as the "Episodes" system for PvE is a lot of fun, it seemed like both styles of play will see lots of use, as opposed to one or the other being the defacto method of leveling up quickly.
Without the entire breadth of PvP content to progress my Klingon character, I was left to repeat the same control point map for hours upon hours. You'll notice, however, that I'm not complaining about it. Much about space combat lends itself to tactical thinking, particularly in PvP. It's not hard to see a strong community focused on PvP existing here, so long as the proper content is made available to them.