Why I see these options are primarily for the sci boff positions, the Vesta being the better supporting GW3.
My problem as floater is Level 10. I clearly need more firepower than a 3/3 sci boat can offer. Dropping the Commander science offers more firepower.
Our fleet is trying to get past level 10 on No Win Scenario. We have been consistently successful getting to Level 8, and for the most part completing level 9 with the option to pause before 10. Keep in mind, we're trying to do this exclusively with in-fleet talent.
I seem to do ok as floater in the Vesta, on both tac and sci captains.
I suspect the tac/FAE combo might be more effective for floater, though, because of the increase in manoeuvrability. Nevertheless, Vesta can give you GW3 + TBR2 plus a CSV/APB element plus some decent heals, which can be a very useful combination for NWS.
Also: I've noticed Scattering Field can be very useful on my sci captain, here.
I tend to hold a side though, so I'm sure there's people around that can give more specific advice
I think Chel Grett has the best boff layout, I used it to beat NWS. Vesta doesn't pack as much punch, and the MVAE hits a little harder but boff layout not quite as good for all energy.
I like with the Chel Grett I can use the ensign uni as sci and be able to run GW1 and TBR1 and still have room for HE1 and TSS1 so you can have the 2 main crowd control skills needed for NWS and still have 2 sci heals. It has just enough tac to be able to run 2 attack patterns, 2 scatter volleys, and 2 tac teams so you cant go wrong with that ship, perfect balance of all the skills needed for NWS, no wasted boff skills.
Breen ship or the Mobius destroyer - effectively the same in boff setup though the breen has a uni ensign slot to the mobius eng and has a 8th rear slot.
As some have touched on the floater is there primarily to save a ship to control the flow of the event, render aid for flanks or the transport but something that is sometimes overlooked is the need to replace a downed flank until they return which might be so long that you have to solo the entire flank for that wave.