The DianSheng Gigaminx is the best gigaminx on the market. It is the only magnetic gigaminx currently mass produced, it is a lot smaller than I would have liked but that is a trend very common with DianSheng's magnetic puzzles, it does suffer from some lock-ups and catches so there is a chance that a self magnetized YuXin may perform slightly better but for most people the DianSheng is easily the best option available.

You can buy it here