There are only 2 choices when it comes to Consistent buffs, that's Rhino and Nova. Other options either can't provide enough of a boost (Equinox) or can't provide it consistently (Total Eclipse Mirage).
Most teams can't accommodate both these frames so here's a short post that might help you pick your team or frame (if you're deciding on which to pick up).
Here's a short summary of their differences based on buffing alone (Roar vs Molecular Prime).
| Nova | Rhino |
Multiplier | Not Power Strength Dependent | Power Strength Dependent |
Duration | Affects Debuff and Range (spread) | Affects Duration |
Effect | Slowly Spreads from cast point Can be recast | Immediate to allies in range Cannot be recast |
Other Effects | Explosions deal damage Debuff also slows up to 75% or Speed up enemies by 30% | n/a |
Multiplier
In this post I'm not going to include the Roar Augment to keep things simple.
Both can deliver (potentially) double damage. Nova does it by default as any enemy that is affected by her debuff will receive double damage. Rhino Can potentially hit double damage and can even exceed it capping at 2.49 times.
So if you are a Vet with all the requisite mods (Blind Rage -BR, Transient Fortitude-TF, Intensify and Power Drift) Rhino is a sure pick. If you're starting out, you might have to focus on your collection first, building Duration before Power Strength.
If you're picking team mates, Nova will be a sure bet at 2x regardless of mods as long as she is at rank 30. Rhino is going to be a bit chancy unless you ask the player for their multiplier before inviting them.
Duration
In terms of Duration, Rhino can sacrifice this and still provide effective damage multiplication (as long as he keeps on using it) while Nova's debuff duration and range is dependent on duration mods.
At 50% duration Rhino will just have to recast more often, while Nova on top of having to recast will have her coverage affected as well.
This is one consideration you'll have to make when taking a Nova into a large map.
Effect
Nova's Molecular prime spreads out from the cast point while Rhino's affects all allies in range immediately.
Again this has to be considered based on how big the map is. Bigger maps will see slower coverage while Rhino can be effective regardless.
Another consideration is that Rhino's Roar cannot be recast. So if you miss cast your roar and miss the damage dealer for any reason, you will not be able to recast it until the duration runs out.
Other Effects
Molecular Prime, being an ultimate has other effects when you cast it. The debuff can either slow of hasten enemy movement depending on your Power Strength. Aside from this, enemies that are killed while debuffed by Molecular Prime will explode and deal damage to nearby units (affected by power range).
Rhino's roar doesn't have any additional effect.
Conclusion
There are a lot of things to consider when making choices for either team mates or for personal use but Mods will play a very important role in your choice. Also consider that not all the players in recruiting will have all the necessary mods maxed.
Assuming equal mod levels and that most of the mods were obtained...
Rhino will excel at providing raw damage output consistently regardless of map size and when in coordinated teams. Consider Rhino for missions that just require destruction (like exterminate or... Draco).
Nova will be able to provide double damage and crowd control (or speed for farming) that will become slightly less effective on bigger maps. Nova Can be very effective when farming (speed variant) or at control (slow Variant) for defense, Mobile Defense and Interception.
Which is your personal pick?
Thanks for reading.