The FRV-1 were and still are overpriced. And they filter the crap out of highs of the incoming signal. And they only do one thing. That one thing is pretty ok, but petty far down the totem pole from an actual spring reverb tank. The Tre-verb has the functionality I'm looking for, but it sounds alot like most other digital spring and tremolo pedals to me. Simplified and generic and digital. I think the Strymon Flint sounds better overall. The Flint leans on the dark side and has it's digitalness, but it doesn't sound generic. And the harmonic tremolo on the Flint sounds nice.