All week long, I like that hasidic sefard congregations do their hoshanos after halel. Its a nice convenience that I presume was originated because the earliest Hasidim weren't patient enough to stay until the end (1). On Hoshana Raba though, I prefer to pray with my own people. This is because some Hasidim blow the shofar after each circuit today (2) and I deeply dislike the practice. Additionally, it seems anti-climatic to do the 7 hoshanas, and the willow whipping before musaf.
MFY (on Twitter) says blowing the shofar today connects the Hoshanas to Joshua's 7 circuits around Yericho. He also says that shofar and prayers for rain go together like kugel and kishka. The latter idea has plenty of merit (3); I'm not sure about the former: Seven is a magic Jewish number (4). That's likely the common source for both Joshua's march and our trips around the bima today.
We started praying at 8 and were done before 10. Not bad. Some of my hasidic friends are still in shul, and can expect to be there until at least noon. This is because the davening is very long, but also because Hasidim treat it like a regular holiday, with holiday tunes, singing, a sermon, aliya auctions and mi shebayrachs at torah reading. Some also duchan.
Some, no doubt, will find this video deeply spiritual, and perhaps "moving". Not me. At best this is ostentatious behavior. At worst... well, draw your own conclusions.
Incidentally, the weirdest idea I've ever heard about the lulav is that it serves as a spiritual "antenna" used to collect, or attract, or to otherwise draw in various and vital spiritual "energies."
(1) I made that up. I have no idea why, or even when, this custom was created. (I should look it up) However, the reason I invented fits with what I know about the earliest Hasidim and also creates a nice irony: Nowadays, those who daven ashkenaz are the ones who, per stereotype, duck out early.
(2) Not all Hasidim do this, but it seems relatively common.
(3) See any Mishna or Rambam on prayers for rain. Shafar blowing is always mentioned, and the last part of today's prayers are for sustenance.
(4) This explains: http://judaism.about.com/library/3_askrabbi_o/bl_simmons_seven.htm. It all started, by the way, with the seven visible planets.
Search for more information about Hoshana Raba at 4torah.com.