Are there disagreements between Reformed Theology and the teachings of A.W. Tozer?

Are there any known conflicts between the teachings of A.W. Tozer and those of Reformed Theology? My concern is sparked by his relation to the Christian "mystics", which sound potentially heretical. This question arose from finding numerous books related to the Holy Spirit written by Tozer when browsing Amazon. Note this question is NOT "Is A.W. Tozer a Christian?".