A comment on one of the earlier posts led to the idea of writing about Chassidim and Ashkenaz. I will try to collect some of what I know about this.
The attitude among Chassidim to minhag and nusach Ashkenaz was not and is not uniform. Nor uniformly negative. Some harbor positive feelings toward it. There are many remnants of Ashkenazic practices among Chassidim, and, when it comes down to it, they are still Ashkenazic Jews. Despite having changed in davening from nusach Ashkenaz to what they call ‘nusach Sfard’ or nusach Ari, they still basically follow a more or less Ashkenaz path in other matters of halocho, e.g. following the Rama instead of the Beis Yosef.
Even in the nusach of davening, there is a great amount of variation among them. There are quite a few different Chassidic siddurim. In recent years especially, various Chassidic groups have put out new siddurim with their own nusach, which they use, as opposed to generic ‘nusach Sfard’ siddurim. No single one that is used by all Chassidim. And some are not as far from Ashkenaz as others.
I have heard that the nusach of the Belzer Chassidim, especially in shemoneh esreh (?), is very close to nusach Ashkenaz (I am using the term Ashkenaz here loosely and not getting into differences between Eastern and Western Europe, etc.). If I remember correctly, the nusach of the Bostoner Chassidim, which claim a connection to the Hafla’ah, is also not that far from Ashkenaz, at least in terms of the shemoneh esreh. As I stated earlier, one Rebbe, the Cieszanower I believe, davened nusach Ashkenaz. I have also heard that the Noam Elimelech, one of the great Hassidic founding fathers, in the back of his sefer, where letters are printed, has a letter which touches upon this and he is actually okay with nusach Ashkenaz as well.
The Komarno Rebbe was very strongly in favor of the old Ashkenazic minhog that only one person says kaddish at a time. I believe there are other areas in which the Komarno was also in agreement with Ashkenazic minhog as well.
There has actually been confusion among Chassidim about how far to go in their adoption of Sepharadic practices. For example, on some occasions there are differences of opinion between Minhag Sepharad and Minhog Ashkenaz re what haftoroh is read. In such cases some Chassidim have gone along with the Sepharadic practice. But others have stuck to the Ashkenaz one (I believe that is the practice of most of them). One of the previous Munkatcher Rebbes wrote about this issue. This I heard in the shiur of Rav Hamburger in Lakewood last year.