After hearing so many times that Ulduar vehicles scale with gear, you'd think I would realize Arena/PvP gear works too, not just PvE pieces... but hey, better late than never!
If you don't know what I'm talking about:
Currently, the honour-only non-set pieces start at ilvl 226, with last season's Arena armour at ilvl 232 and weapons at ilvl 239. If you're lucky enough to get drops from Koralon (or good enough at Arena to get the current season's rated Relentless Gladiator gear), the ilvl starts at 245 for non-set pieces and goes up to 251 for weapons.
PvP gear is relatively easier to get than waiting for drops in raids, so if your raid is going for Flame Leviathan with towers up and having trouble, you may want to check if swapping in pieces of your PvP set is actually better than wearing your raiding gear!