“good but quite plain isn't it and there are so many other pedals that cover this sound entirely plus more, dunno why someone would get this where there's so much better available.”

60% of 15 verified owners recommend the Holy Grail Nano Reverb, based on real owner verdicts aggregated from Reddit, enthusiast forums, and YouTube.
The headline score reflects owners (Reddit, enthusiast forums), independent lab tests, blogs with no affiliate links, and YouTube owner-comments when they line up with owners. is shown for perspective but kept out here — hover the i for why.
Synthesized from what Holy Grail Nano Reverb owners say — not a spec sheet.
“good but quite plain isn't it and there are so many other pedals that cover this sound entirely plus more, dunno why someone would get this where there's so much better available.”
“I had one for awhile, and I liked it, but liked my other reverb pedals more in the end.”
“Great simple reverb. If you’re looking for huge trails, etc. it’s not what you’re after but if you want an easy set and forget, solid sounding reverb it’s still hard to beat, especially for the used price.”
“I have the nano but same... Spring always on. It was my first pedal and I don't think I've ever turned it off!”
“The Grail sounds ok, but doesn't have a lot of control, as it has only one knob. When that knob get past noon, it starts blending out the clean signal, so I found only half the knob's range useable.”
“Had one and it shit out on me disappointingly fast. Sounded nice while it lasted though.”
“I love the spring verb on this. It used to be my go to when playing small combo amps without a reverb tank.”
“Really, I think it's just not a well designed pedal. There's zero need for the amount of reverb that this thing is capable of pumping out.”
“I have a Holy Grail Nano and I like it a lot. One simple knob, and nice Spring and Hall tones.”
“I have one and I personally hated it. But it depends what you’re going for”
“My nano is always on. Plus the smaller footprint is better for me.”
“It's extremely simple, but it's this pedal main strength.”
“Holy grail nano is legit. Spring sounds great on it”
“I have a Nano and it’s my desert island reverb.”
“The holy grail for its elemental simplicity”
Practical notes owners raise — setup, quirks, and issues to watch for. They don't say whether the person likes the product, so they're not counted in the score, but they inform the pros, cons, and who it's for.
“Those are going to be very similar with I think the main difference being you get an additional type with the neo , or you lose the flerb. Check out the holy grail max or plus for more feature”
“So both are going to have Spring and Hall, but the Plus has Room and Flerb, while the Max has Plate and Reverse. Basically, a lot of the sounds are going to be similar, the differences are slight.”
“Past that point, the reverb volume increases but the guitar (dry signal) decreases. Cranking it full right gives you 100% wet, or close to it. I have the holy Grail nano and that is how it functions.”
“The two versions pictured here are the same, just a new chassis art design. The Neo is different, as other have pointed out it has Plate instead of Flerb.”
“This is weird, but I recently know the same thing. I now play with spring at like at like 15% of max. And it is super wet and drippy.”
“Nano has Spring/Hall/Flerb. Neo has Spring/Hall/Plate. Never saw a use in Flerb so I went with a Neo.”
“I’ve had a couple Holy Grails and I believe they are completely dry with the knob fully CCW.”
“Cosmetic variations only, they sound the same. Middle is oldest, right is newest.”
“Nano and "with flerb" (even though neo and nano have flerb) are the exact same pedals. The difference between the nano is flerb changing to plate. The plus then adds a control and has room instead of flerb. The max has plate and reverse. So overall the core hall and spring are the same.”
“Ah I see, I am just using the hall function most of the time.”
“Neo has a plate reverb instead of the flerb on the Nano.”