3.1 PTR mana regen testing

I logged into the PTR over the weekend to do some DPS testing and mostly to take a look at how the lower mana regen will affect my current arcane build. I tested my current arcane spec DPS vs the heroic target dummy (raid boss level dummy), and came out with 1927 DPS WWS data. I only made it through my first mana gem and 1 evocate before I was OOM. This kind of hints that I'll be facing serious mana issues when I raid with this spec unless we have the replenishment buff. I was curious to try the dual spec out also, so I visited my trainer and purchased dual spec for a cool 1000g. I specced frostfire to check out their mana regen, and visited my same ol target dummy and lit him up again, this time only doing 1730 DPS, with this build. Again here is my WWS data. I was able to use my 1st mana gem, then evocation, then the 2nd use of mana gem before I was OOM. It seems that mana is less of an issue for this build, so I may be adopting FFB as my secondary spec in future. Of course I do still love the frost build, and the ability to give my raid the replenishment buff would in fact be awesome, so I can't say I'll make that call just yet. I will probably just come down to the decision of what our raid needs, DPS or replenishment. I may even end up respeccing into FFB as primary and frost as secondary. What do you plan to use your secondary spec for?