Finalli got around to testing Haste Samba. Thanks to Saitohajime for sitting /w me in Kuftal and hitting crabs for the better part of half an hour.
Note: Saito is 75 DNC /w 2 merits in Haste Samba~
Test 1: Is Haste Samba Magic?
75DRK /w Apoc(513 Delay)
SV'd Marches + Haste Spell Only (43.75%)
7 Hits - 6 Attack Rounds
~254 Delay = ~50.5% Haste
50.5% - 43.75% = ~6.7% Extra Haste
This test confirms that Haste Samba is working on top of the Magic Haste Cap.
Test 2: Is Haste Samba JA Haste?
75DRK /w Apoc(513 Delay)
Hasso + Last Resort(Lv 5 DB) + Haste Only (~39.65%)
6 Hits - 5 Attack Rounds
~313.6 Delay = ~38.87% Haste
39.65% - 38.87% = ~.78% Haste
There's a bit of extra haste... In my opinion this is just margin of error. I feel strongly this is proof that Haste Samba is considered JA Haste.
Test 3: Combining Hastes~
75DRK /w Apoc(513 Delay)
Hasso + Haste + 20% in Eq Only (44.24% Haste)
102/1024 + 150/1024 + 201/1024 = (44.24% Haste)
6 Hits - 5 Attack Rounds
~253.6 Delay = ~50.57% Haste
50.57% - 44.24% = ~6.33% Haste
I only did these three tests, and while they're subject to some amount of error I feel the results are clear. Although more tests would provide a more accurate number it seems likely the following is true:
Haste Samba is 50/1024
Each Haste Samba Merit is 10/1024
Haste Samba is JA Haste
Since Saito had 2 merits, this would be 70/1024 = 6.84% JA Haste. Which works nicely with my experiments.
I think the reason there is extra haste in Test 2, is that JA Haste might cap closer to 250/1024 instead of a hard 25%(256/1024). This is just speculation though.
EDIT: Just thought I would add this to make a meaningful discussion~
Haste Samba is the only JA Haste 1Hers can get. MNKs NINs etc... can now go above the Eq/Magic Cap and almost reach the hard cap themselves.
This also means that if you use Souleater + Kraken, you can reach ~78.5% Haste. (Supposedly Bloodweapon doesn't stack /w Samba =x.) Thats intense!