I am currently trying out a stamina Templar. Jabs is really good in pvp, very high damage if you spec right.
The CC immunity is very annoying, but sometimes it helps with finishing off opponents who can't CC break as fast as the pros.
The biggest thing you will find about jabs is it is very hard to land all 4 of them, people will dodge roll or sidestep it. You generally have to be spoon-fed to get kills. Biggest thing is stun -> jabs.
I am on a Imperial Templar and I wouldn't change. I have almost 29k stam with food buffs and my jabs can hit pretty hard. I am not sure how Orc will change things though.