Yes, for pvm mages who are 100% of the time in protection faster casting is pointless. But to every other class and build in the game it is not. That was the original issue with the item was not so much the stats that could be found on other things, but the faster casting coupled with those stats. This blows helm of swiftness out of the water and should not even be compared.
If you think FC1 was really what made it OP, imho, drop the FC1. Dropping 25% of the SDI, 50% of the MR, and 33% of the LMC was overkill.
I see your point about the Spectors lenses, but even as this stands now, it's generally better than Spectors. With all the changes to it, adding resists and lowering the rest, it makes Spectors kind of redundant:
[xtable=skin1|689x164]
{tbody}
{tr=@x26}
{td=219x26}Original Halo{/td}
{td=97x26}Halo v2{/td}
{td=98x26}Halo v3{/td}
{td=98x26}Halo v4{/td}
{td=98x26}Spectors{/td}
{/tr}
{tr}
{td=219x@}+mana 15, +mana(int) 8{/td}
{td=97x@}+mana 15{/td}
{td=98x@}+mana 15{/td}
{td=98x@}+mana 15{/td}
{td=98x@}+mana(int) 8{/td}
{/tr}
{tr=@x26}
{td=219x26}MR 4{/td}
{td=97x26}MR 4{/td}
{td=98x26}MR 4{/td}
{td=98x26}MR 2{/td}
{td=98x26}MR 4{/td}
{/tr}
{tr=@x26}
{td=219x26}SDI 12{/td}
{td=97x26}SDI 20{/td}
{td=98x26}SDI 18{/td}
{td=98x26}SDI 15{/td}
{td=98x26}SDI 12{/td}
{/tr}
{tr=@x26}
{td=219x26}LMC 15{/td}
{td=97x26}LMC 15{/td}
{td=98x26}LMC 15{/td}
{td=98x26}LMC 10{/td}
{td=98x26}LMC 8{/td}
{/tr}
{tr=@x26}
{td=219x26}FC 1{/td}
{td=97x26}FC 1{/td}
{td=98x26}FC 1{/td}
{td=98x26}FC 1{/td}
{td=98x26}---{/td}
{/tr}
{tr=@x26}
{td=219x26}0/3/5/8/8{/td}
{td=97x26}15/15/15/15/15{/td}
{td=98x26}15/15/15/15/15{/td}
{td=98x26}15/15/15/15/15{/td}
{td=98x26}5/10/14/20/20{/td}
{/tr}
{/tbody}
[/xtable]
In other words, the changes that have been made to the Halo are basically turning it into Spectors with FC1. As of v2, this was an awesome PvM piece, opening a lot of flexibility for PvM mages.
There's been few enough items to bump max SDI; even that 20 bumped the max +2, which was significant for PvM.
As for resists, I've been assembling a high end PvM suit where I planned to use the Halo, once it goes global. I'm building all brittle/clean, but if I were using antique parts, these numbers would be even higher (though the suit wouldn't last so long). So using that suit as a reference...
That suit's resists are 130/80/74/73/96. 15/15/15/15/15 vs 0/3/5/8/8 only looks good; it's pretty meaningless in reality.
FC is meaningless due to protection.
With the new LMC 10 on the Halo, LMC on the suit is still 48 with a 40 cap - ie, for this suit, whether LMC is 10 or 15, it's still a meaningless difference.
With the latest change, MR on the suit goes from 19 to 17, but MR's not really important - my int's at 150 and the suit has +33 int and +41 mana. That's 224 mana I have to dump, on a meditateable suit, with both 120 meditation and 120 focus. Esp because MR is subject to diminishing returns, MR 2 or 4, it's pretty meaningless. At MR 4, I get 3.3597 passive recovery, vs 3.2889 at MR 2. That's all of 0.07 less mana per second... ie, also meaningless.
So that leaves ONLY the SDI as meaningful. At 20 SDI, the Halo's an easy choice. At 15, I might use it, but I'm still shopping for a legendary with 18.
Oh... and the kicker... this is a
high luck mage suit (1940), where the Halo was the only non-luck piece I was using, for the SDI. If I wasn't worried about luck, with a few item swaps, I'd be at FC 3 or 4, well over 30 on MR, and over 100 in every resist... and then literally the ONLY reason to look at using the Halo would be the SDI.