All I have heard/read about it is that seachem matrix is not a bad bio media. Has good quality. If you buy it as a really nice bio media, then go for it. If you expect it to magically turn all nitrate into nitrogen gas, then don't waste your money. Exporting nitrate takes a long time (compared to turning ammonia into nitrite and nitrite into nitrate). It will help some, but you still need to monitor your nitrates and have other ways to export nitrate (e.g. a refugium helps, or carbon dosing combined with skimming helps, water changes help).