The Meris Mercury X sounds pretty intriguing. It would be interesting to hear some examples of it with the 3rd Wave as the source.
Another pedal that has caught my attention (and my purchase) is the Walrus Audio Meraki. Mentioning it on a thread/discussion titled "best reverb" is kind of off topic since it is a delay pedal. But it very much can sound reverb-y and produce similar effects that I typically would coax from a reverb pedal. It has a lovely sound. It certainly excels at stereo pingpong delay and similar but with the mix turned up and the left/right feedback set high, it produces a wash of ambient reverb joy. I'm having a lot of fun with it, but I've only had it for a couple of weeks, so it remains to be seen if I will use it much on any recordings. I already did use it on one track for some echo-h space-y piano sounds.
I suspect that this pedal would appeal to many on this forum since it is all analog. But it is also spendy for "just a delay". About the same cost as the Meris Mercury X. I had some "atta-boy" money from work that has to go to "gift card" types of things, so it was a splurge that didn't really affect my pocket book. However, now that I have played with it some, I would put it in the category of something I would buy with real money. I'll post back if the honeymoon phase wears off.