Guild Wars 2

Are they worth using with Soldier/zerk (armor/trinkets respectively)?

They heal for 30 hp a sec if you have all 6. While that does seem small, it does add up to a sizable amount of healing power (to get the same amount of healing/sec from either passive or active heals).

I use them on my war with knights/rabid gear, and they’re nice/have served me well.

I think it depends what you want to use them for. If you do want toughness runes, (in my opinion) in general the best two are either Dolyak (PvE) or Melandru (WvW), though with good cleanse and stun breakers you can make do without Melandru.

If you want to use them in dungeons, don’t. Open world is okay since you won’t be impeding anyone. In WvW you have better options such as Melandru. I won’t speak for PvP as I don’t know what is expected there.