From a PvP perspective I'd definitely like to see the defensive Monster sets get a buff. Many of the offensive Monster sets have a 2 piece bonus that is equal to or better than what you can get from the final bonus of the best 5 piece sets.
But none of the defensive sets come close to giving you the survivability of the 5th bonuses of Pariah, Allesian, or Buffer of the Swift.
The armor buffs from Lord Warden and Bloodspawn are pretty small (3100 and 3700) considering they're limited by being confined to a small area or to having a low chance to proc.
The two sets that give shields are both are so small 1 LA in PvP is more than enough to destroy them.
Chudan gives you a buff that every class has easy access to, usually on a long duration ability that often also has another effect that is to important to give up.
Thurvokun's main effects were massively nerfed with the changes to the major/minor. Plus it has a small static area on proc with only 50% uptime.
Vykosa might be decent for PvE tanks but requires a taunt to be slotted if want to use it and giving up a skill slot for an otherwise useless taunt skill to make your monster helm work is a huge downside for PvP.
The clanfear from Shadowrend can only hit a single target at a time and now only reduces their damage by 5% for 2 seconds.
Lady Thorn is overly complicated and slow to apply for PvP with too little uptime on the debuff.
Pirate Skeli's damage reduction gets pretty much negated by the healing debuff it applies to you.
And when it comes to staying alive with a healing set Chokethorn or Earthgore give an smallish HoT (1.5-2k) that is guaranteed only if running solo. If you're in a group the heal might go to a group member letting you, the person actually wearing the set, die instead.
When active Troll King's bonus gives you 463 hps, or enough to heal back half the amount a weak dot will take away, and keep in mind you only activate it when someone is able to drop you below 50% and whatever heal you just used wasn't able to take you back over 50%; so your healing vs incoming damage ratio is probably not going to be balanced out by 463 hps.
The very bottom of the barrel sets are Nightflame, Scourge Harvester, and Sentinel of Rkugamz. All have low uptimes and negligible heals.
Engine Guardian is supposed to be resource restore set but when used for a LOS damage sponge it's probably a better survivability set than any of the above.

Zodiarkslayer wrote: »

Moster sets also compete with mythical item plus generic one piece bonus.
That is an even greater gap.
Sets that only give a minor buff are only useful if you have no other access to that buff. For example in SOLO builds.
Monster sets are becoming more and more obsolete. It is a sad truth.

Infernal Guardian is still my go-to for solo PvE.
It procs off any shield cast like Brawler, Hardened Ward etc, (plus light attacks for some gear/CP combos) and has a great balance of damage and utility.

No, it ain't BiS for either trials or PvP but it is perfect for people like me that like to solo group content.