It is on the Jewish calendar the yarzeit of the Ari. And in a kind of environment in which Talmud is learned all day long I think the Ari is important. But from my point of view the reason the Ari is important is more as  good explanation of Torah. The Ari helps me at least to deal with problems of interpretation.  Arguments from authority aside I should mention to that Yaakov Abuchaztira the ari was simply "rabbainu". That is if you find in the writings of Yaakov Abuchatzaira simply "our teacher" that always refers to the Ari.

But the problem is that we have a definition of "outside books"  as the Rif defines it. The Rif says those are books that "explain the Oral or Written Torah with new foundations or principles that are not already contained in those books." And most of the ideas in the Ari don't seem to have a source in the Talmud. I think the answer to this is that in fact in the agadic parts of the Talmud, you do find things that hint to the basic principles of the Ari.

At any rate, never learn Kabalah with Ashkenazim. They always get it wrong and it has serious consequences when they do.

The best approach is this: If you have a daily session in Gemara in depth [about a hour] and  one learning quickly [also an hour] then the Ari is a good idea to supplement to your daily routine.