Well the ones that are beyond doubt are Helix and Stormsurge, those are the two best merit categories hands down.
Now, Max sublimation is one I am definitely not sure of. For me, I don't always cap out on Sublimation before using it, so having a larger cap seems a waste of merits.
The Modus Veritas category isn't much better, since there's no reduction on its timer possible. So you're blowing merits on something you can only use every 10 minutes. Alternatively, if you are planning to end game SCH with a strong Helix gearset, this could give you a nice chunk of damage out of the gate.
The least useful on the service is the Grimoire recast. That would only be good for someone who is a fill-in type of SCH, swapping on the fly between WHM and BLM in a short period. Even then, your recasts are short enough and the penalties small enough for cross-casting that you can normally wing it.
For me, 5/5 Helix, and either a mix of the other two or piled onto MV.
Group two is a lot easier. The enmity reduction seems nice, but if you are riding the hate that close to the edge, there are more issues your shell needs to address, or you need to learn2play. Hate control isn't just the tank's job. If you are overnuking and not paying attention, the enmity abilities are pointless. As for what Zagen said, honestly in situations like that, you have your helix spells and lower tiers. Better to just work with what you have than meriting like a sonovabitch for the ability to toss one IV Ebuillence powered nuke, then sitting with your thumb up your **** while waiting on charges.
For me, the boosted accuracy of Focalization is the most appealing. By charging that up, it lets you open up more in the +MAB department with less resist worries on some of the bigger mobs in-game. This lets you get the most out of limited-window events like Manaburst openings on gods or nuking in a zerg situation. The WHM equivalent is useless. You won't be debuffing a mob with tier 1's unless your LS has no RDM. The - enmity for cures is the same idea: End-game, you will have other healers, unless you are the one they count on.
So for me, it will most likely be 5/5 Stormsurge and 5/5 Focalization.
Edited, Jul 14th 2009 10:38pm by Pawkeshup