I was in the Na Nach place today (on the name of Rav Nahman of Breslov and Uman) and listening. One thing Rav Nahman said was not to pray with the intensions of the Ari {Rav Isaac Luria} because for those who are on that level it is just the plain meaning of the words and for those that are not on that level it is like forbidden magic.

This gets to a subject that is hard to figure out in the Ari. On one hand he had great insights, but on the other hand  people that get involved in that seem to get sidetracked. And it is not clear why. Maybe it is like is usually said in the Litvak world that it is only for people that have learned Shas many times.

Further as to what Rav Nahman said it is only for those for whom the intensions are the simple explanation of the words, I have to admit I do not see any explanation of the Torah that makes sense to me except  the Ari. Just to give a simple example--the flood of Noah. How can you understand that expect that it refers to מים נוקבין (the female waters)? Or the basic time line of Genesis? How can you understand that except by the Ari? It is not as if the time line is ambiguous.  It does not come out to be 13 billion years. It comes out to be a very specific number of years are 7000 [counting the years of life of all those people from Adam until Abraham and from him until Moses and from him until the first Temple.]] Unless you explain the Seven Days of Creation as referring to the seven lower sepherot, it makes no sense at all.

So what I suggest is in fact to pray with the intensions of the Ari in the Sidur HaReshash.  Now there are two sidurim of the Reshash. The three volume small one I think is not any more well established than the large one from the grandson of the Reshash. It is called on the name of the Reshash, but was actually put together by students of the Reshash. I think the large one [five volumes] is better. 

But I agree with the Litvak world that all this is only if one has gone through Shas a few times.