Yes, the weight of the glass really IS harder to lift up, than it is to drop
it down.
Yes, it is binding on something. You can hand assist partly, by pulling it
up, pulling your hand away before it gets pinched.
Dirty felt tracks increase the drag a lot.  Blow out the tracks with
compressed air to clear as much of the dirt as possible.
Then, lube the tracks with silicone spray.   It'll need to be done at least
annually.
You could replace the felt tracks and clean the glass edges while it's out.

Mike B.

-----Original Message-----
From: HotelWestfalia
Sent: Sunday, July 24, 2011 8:06 PM
To: vanagon@GERRY.VANAGON.COM
Subject: What's the holdup? Power windows ...

Greetings to the Honorable List,

I'm baffled by how slow it goes up but going down is fast.  Going up is like
a struggle, yet the glass is not binding to anything.  I'm wondering what is
it that makes it so slow going up.  Without the glass it's fast going
upward.  And the glass is not really heavy.  I can't think of anything
radical.
Maybe there is one of you who solved this riddle before.

Zoltan