Depends on your application with the stylus. If you wish to annotate and/or highlight stuff, better with the Jetstream/Flyer. Used the stylus of Samsung Galaxy Note and I wasn't impressed with its opton for note taking and annotations. The inbuilt/stock PDF viewer on the Jetstream is way way better. If you want the Sam function on the Note, you need to use eZpdf or something else.I am not saying that is a bad option,but I somehow prefer the stock PDF viewer with Jetstream for annotation and stuff. If however, your main use of the stylus would be only occasional use for signing documents or using it for occasional notes, then you could go in for either. I do not know the specifications of the Note tab. So best suggestion would be to wait for its release, read up some reviews about it before taking the plunge for either of them.
Regarding the Jetstream, only drawback with it which I can pinpoint is that HTC doesn't provide us with timely updates and that may not seem to be the case with Samsung. So if that a priority,then Samsung may be a better bet. Recently helped a friend of mine chose between the Note phone and HTC Flyer. He got the Flyer and has been happy with it compared to the functionality of the stylus and stuff in comparision to the note, if that helps.
Hope you get a device just right for you, but do so only after seeing complete specs and a few review of the Galaxy Note Tab.
Sent from my HTC PG09410 using XDA