If you want something that sounds like an affordable reverb box from the 1990s then Valhalla Room is awesome.
If you want a reverb sound that doesn't sound like you have used any reverb, but just happened to record in the most ideal place for the content you have recorded, then the Exponential Audio is awesome.
On it's best day, Valhalla sounds like a great effect and that can be just what you want. The Exponential Audio reverbs make stuff sound rich, full and deluxe without revealing that you have used an effect.
I'd encourage you to demo both.
best regards,
mike