When I first started the game, I intended to PvP a lot on my Fed, who I still consider my "main". I was just going to pvp some on my Klingon alt to get a feel for the enemy. However, due to the queue times (I don't want to wait 10-20min, then have a mission interrupted), I mostly PvP on my Klingon.
Most of my fed pvp experience is at the end of tier 2. Of course, on my Klingon, I've pvp'd all through T1 and T2 levelling. My general take is battecloaking out of a losing situation is not the "lalala can't catch me, I'm the gingerbread man" that I thought it was while I pvp'd as a fed.
When I first started battlecloaking in T2, I died pretty much everytime. Then I started getting better at. Its mostly a matter of timing. Both looking ahead 10-20 seconds to know generally when to cloak, and specific timing (ie not when torps are headed at you). Even then, its a gamble.
There are certainly ways to make it less a gamble. Basically, ditching out of a losing fight means using: Brace-Cloak-Evasive-Engine Battery. And even then I find myself escaping with just 0-5% hull remaining. (0% I'm assuming is rounded down less than 0.5%)
Mostly I've been doing this to see how well it can be done (I do kinda want to pvp more as a fed), and as one of the previous posters put it, just to see if I can pull it off as a personal accomplishment. I certainly have had the feeling staying in the fight will get me respawned and fighting again faster than skulking off cloaked. Still, I tend to be in the top 3 damagers (mostly cause I time my torpedoes right, not that I'm otherwise a great pvper, kinda above average at my best).
I should note that I mostly play the Cap and Hold maps. Living instead of quicker death-respawn can be useful, because after you've escaped the fedball at one location, they tend to hang around there, while you and your teammates can cap the others.
Also, I've fought fed players that laugh off my battecloaking and just kill me despite my best effort to escape.
I will say this, if I designed a competitive pvp game from scratch (no lore to follow), I would not include stealth at all. Its very difficult to balance out, doubly so if only one side has it.