Why Magnesium L-Threonate is the Best for Brain Health and Sleep

I have been seeing a lot of marketing for Magnesium L-Threonate lately claiming it is the only form that can effectively cross the blood brain barrier. I am wondering why magnesium l-threonate is the best for brain health and sleep compared to the cheaper forms. I am in the UK and I am willing to pay more if the cognitive benefits are real.

I am looking for something that helps with mental focus during the day and deep sleep at night. I have heard that this specific form of magnesium can actually improve memory and learning. I am a bit skeptical but the research seems promising.

Has anyone here switched to L-Threonate from a different form of magnesium? I want to know if you noticed a significant difference in your sleep quality or your mental clarity. I am trying to decide if the high price tag is actually justified for a serious lifter!