Allow me to help you guys.Ionic Clay and Hard Rock are two very...

Allow me to help you guys.

Ionic Clay and Hard Rock are two very different animals with different characteristics and objectives.

Hard Rock projects are the main source of critical LIGHT rare earths (CLRE), Neodymium and Praseodymium.
Ionic Clay projects are the main source of critical HEAVY rare earth (CHRE), mainly Dysprosium and Terbium which are considered critical by governments for defense and research applications.

Both produce a bit of the other as well.

From a Nd and Pr perspective, Hard Rock projects are usually superior due to higher grade and lower surface environmental footprint (if non-radioactive).
From a Dy and Tb perspective, that relation is opposite. Ionic Clays tend to be enriched in heavy rare earth elements above hard rock level due to weathering and ionic absorption.

Ex : LIN has average 18ppm Dy and 5ppm Tb.
MEI has average 40ppm Dy and 8ppm Tb.
LIN has average 5000ppm Nd + Pr
MEI has average 1000ppm Nd + Pr

Dysprosium is worth 3-4 times more than Nd/Pr
Terbium is worth almost 20 times more than Nd/Pr

If you place yourself from a CHRE perspective, clays are vastly superior. It's clays, so it's free-digging material. If it's ionic, you can just wash it with salts like ammonium sulphate. All of this means it is very low capex and very low opex per ton processed to produce a concentrate.
There's no fine mill crushing and complex metallurgy usually required with hard rock projects and you still produce a decent amount of Nd and Pr.

But again, if you place yourself from a CLRE perspective, hard rock projects are better usually due to higher grade and lower surface environmental footprint, especially if non-radioactive.
In the end it's all about the basket price and the economics per ton processed.

Looking at their numbers, I wouldn't call MEI a pump and dump. They proved their project is Ionic in nature which is critical. 85% of their holes ended in mineralisation. The grades are excellent for a Ionic Clay project.

Now they mostly need to make sure there's no radioactive issue and make a proper environmental and remediation plan for the large zone impacted and this is very likely to become a mine.

Disclosure : I hold LIN and not MEI.