I broadly agree with falcoso; it's a strong list, for sure.
They took a hit, definitely, but they were so good before that a nerf is kind of expected. They're a fast, very resilient melee threat which this list otherwise lacks so I think they're solid choices here. The Gauntlet of Fire is probably unnecessary; I'd swap that out for a Phylactery, but apart from that it's great.I'm not sure about Command barges as well, I haven't really used them but from what I hav heard they have taken a massive hit,
With only 10 Immortals, I think paying a hair over 100pts to give them +1 RP and have a dude with a shitty Lascannon is definitely on the pricey side. You want to be maximising the number of RP rolls that Szeras buffs; he seems like a very good choice for a list that's shoving big squads into someone's face but not for a list bringing minimum troops to hang back. Likewise, an Overlord isn't really doing anything since he's tanking for a squad worth less than he is. A Command Barge is the best choice for a solo HQ when, like most 750pt lists, you can't maximise the utility of another HQ.I would say you would be better of with someone liek Szeras (for his +1 bubble on RP for the immortals) or even just a standard overlord to sit at the front and take the hits with nightmare shroud?