My Grail from Brookdale came in today, along with my Modern module from Stevarino (thanks again Steve!).
Just so you know when I was testing it compared to my Mesa Dual Rectifier I was running my Randall RM100 with a Sonic Maximizer Stomp and a Yngwie DOD signature Overdrive Pedal (his newer one) for a tighter overall sound. I've found that with most of my MTS modules these two pedals in combination really bring out the most in the modules with more clarity and articulation. Except for the Blackface, Deluxe and the Modern - those are ones I don't run these two pedals with, too much of it fighting them.
I have to agree with Rick on this one. The Mr. Scary has way more cutting power and substance for leads than the Grail. I was really surprised that the gain on the Grail is pretty low compared to my Dual Rectifier's. The low end on the Grail falls short as well. I can get it pretty close to my Dual Rec tone, but probably around 80-90 percent tops. Now that is also because this isn't a true "Rectifier" module to give us the full spectrum - but rather a selective tone definitive of Lynch's newer stuff from recent years. I can definitely dial my Rectifier in to the tones of the Grail - just that the Grail can't dial in the higher gain/smoother tones that I am used to with my Dual Rec.
Compared to the Recto and Rectified though - I think this comes closer to my actual Dual Rec tone - so if you're debating between one of the previous two and this I'd go with this one, to my ear it is more approximate with Mesa's tone.
Once again I agree with Rick in regards to high gain modules - I dig the 1086 as the best high gain module so far for the MTS line. Second is the XTC for a slightly "smoother/creamier" gain sound and the SL+ after that. Also the new UltraXL has quite a bit more gain as well compared to the Grail - but keep in mind that is based more on a "Dimebag Darrell" tone and tends to sound more compressed, but is still a great high gain module I think.
Now I'm not bashing the Grail - I do really enjoy the tone from it - it has a good gain section, just don't be expecting to have the full Dual Rec capability with this one - it does about 85% of the gain of my Dual Rec, it is just the max portion on my Dual Rec, it can't do. Also the bright switch on this one does a good job of breaking up the tone a little bit more for me compared to some other modules and this switch (sometimes w/ others I can't tell much of a difference when I switch it).
So there is my review on the Grail from the 1st day playing with it. I'll mess around with it more in the next few days and if I find some more info I think would be useful I'll post it.
----> Note: I did like how Randall used knobs like the Dual Recs too