I'm actually alright with the changes to the Nemesis Force Weapons. While less potent in some situations, the weapons are now more broadly useful and generally cheaper to boot.
Psycannons moving from the old dual-profile to a straight Salvo type makes sense, though it does drop their efficiency down if one is equipping Power Armour units with them. They're still usable with the Power Armour units, especially with Combat Squads, but I think it's more appealing to put them on units in Terminator Armour.
Psilencers lost their ability to wound Daemons on a 4+, but picked up Force. It's probably a wash to be honest. Force is more broadly useful, but requires a Psychic Test. Wounding Daemons was very situational, but worked automatically.
Incinerators picked up Soul Blaze and generally dropped in cost. They were quite good before and they got better. Always a nice thing.
Locator Beacons popped up in the Vehicle Equipment section, which was previously limited to just Teleport Homers.
Psyk-Out Grenades gained a ranged profile, which is handy given that pretty much every unit has them.
Relics of Titan:
Some neat bits here. The Bone Shard of Solor and the Fury of Deimos are neat, but probably staying on the shelf most of the time. That being said, using Fury of Deimos to add Precision Shot to a character isn't a terrible use of 10 points, there are just other, better relics in the book.
The Cuirass of Sacrifice looks neat. 15 points to add Feel No Pain and It Will Not Die to your Warlord isn't a bad buy. Adding Eternal Warrior would have been nice, but getting that USR from wargear seems to be going away across the entire game line. Even if it weren't, I wouldn't expect to layer that on for a mere 15 points.
The Domina Liber Daemonica is great if you're taking a Sanctic Daemonology Librarian or Grand Master since it essentially gives you up to four rolls on Sanctic Daemonology or a bonus power from that tree if you're splitting your powers up. It's fairly specific though, especially since you're probably not focusing one of those characters on Sanctic Daemonology. With the automatic Psychic Powers in the rest of the army, you have very reliable access to Banishment, Hammerhand, Sanctuary and Cleansing Flame. That leaves only Gate of Infinity, Purge Soul and Vortex of Doom. Gate certainly offers some good utility. The two Witchfire powers though have lots of failure avenues, some of them rather perilous. So, the book is a nice buff, but you have to be looking for something fairly specific to add it on, especially since I'm pretty sure it'll cost you the free Primaris power if you're taking your abilities from any tree except Sanctic Daemonology.
The Soul Glaive is essentially a 20 points Nemesis Force Halberd which grants Precognition when Force goes off. It's a possibility to add to a character. Unfortunately though, the character that I'd really like to add it to is a Brotherhood Champion who can't upgrade his equipment. Still, not a terrible upgrade for a Brother Captain or Grand Master, especially if you're not rolling on Divination with them.
Finally, the Nemesis Banner can be included in a unit of Paladins for 35 points. At 10 points more than the Brotherhood Banner, granting Fearless to friendly units within 12" and +1 Attack to the unit and Dangerous Terrain to Daemons, the Nemesis Banner is probably worth the 10 additional points over the Brotherhood Banner if you're adding a magic flag to the unit in the first place.