I used Juggernaut for some time in the past. The nerf to the heal down from 20K (PvE value) was significant. The set activates when you're in trouble, but doesn't heal you enough now. You still have to recover and that eats into your high armor time. It's not a great set for going on counterattack, at least not on my nightblade. DK might be different, but then a DK probably doesn't need the set.

Some opposing nightblades have hit me right through the Juggernaut threshold and the set never procced. Some IC guard NPCs breathe on you, and the set procs for no reason. It's not the most reliable thing in the world. It's still better than Blessed, though. The problem with Blessed is ... well ... I was trying it on my high mobility NB as a back bar. You don't want that. You have to block something to activate it. Blocking slows you down. Sometimes people don't hit you when you want to activate the set. So you have to choose whether to stand there or not block and move faster. Again, it didn't fit with the character I used it on and, again, something like a DK, who naturally blocks much more, probably doesn't need it.

Beekeeper is IMO not good, even if you want to build into health regen. I suppose it works in Ravenwatch, so there is that. Otherwise: Gaze of Sithis (or Troll King), Eternal Vigor, Endurance back bar, damage set front bar, Strategic Reserve CP at 500 ult. With passives and potions, this adds up to about 4K health regen in PvP. The ideal class for that is sorc, because (a) sorc needs the healing and (b) sorc can keep Strategic Reserve up by using Overload and (c) not being able to block, due to Sithis, is something a sorc can deal with (by streaking). Do I recommend that build, though? No, not really. Too much of a damage compromise and Sithis - not being able to block - is just not very good.

If you want to make a tanky templar, well Radiant Ward or rather Blazing Shield with a 45K health build is something Kristofer did a while ago, while simultaneously running a high weapon damage build. The inherent benefit of looking tanky - the high health - is it keeps gankers away. It's also not a bad approach. I tried it once. Ward and Spiked Bone Shield. It's a weird build. It kind of worked, but I didn't really take to it.

My idea of a tanky magplar is Lightning Staff front bar (buffs Sweeps, good for magicka restore), 1H+S back bar. I use Shield Wall as often as I use Crescent Sweep on templar. It plays well while you try to pressure people. I also like Zoal quite a lot. You could be tanky, but Zoal really saves your bacon when you get jumped by several players. Mobility comes from Race Against Time or Mist Form. In terms of sets I don't play my magplar much, but run Rallying Cry front, Wretched Vitality back bar in CP, and Deadly Strikes plus Amber Plasm in Ravenwatch. Stam sustain is more important to me than being tanky.

Of course the more meta way to play is probably dual-wield front bar, Vateshran ice staff back bar. I think Deltia had a build out a while ago and he actually eschewed Extended Ritual for Mara. Mara will get nerfed though. Everyone is saying to use Hist Sap now. For a magplar a light armor set is not a bad choice.

I would personally only wear Vigor if I was making a health regen build, meaning you tune everything for that. Vigor on it's own is not something you will really feel. So, if you want to explore that direction, sure, but I think this mainly serves a purpose on a sorc. On a templar I wouldn't really go for that. Wretched Vitality is a better sustain set and can be back barred. Simply dual-regen food may also work on the sustain front. Healing on magplar comes from Sweeps, Living Dark, Honor the Dead, Radiant Glory, Extended Ritual, all of that already heals you.

Also, I actually like Restoring Focus on magplar, e.g. the stamina morph. It's another way to cover your blocking / rolling / sprinting sustain, one that keeps going while you block. You gotta play around with that for your preference, though.