Weight isn't an issue for my Arisen. All I bring with me to the fight are a dozen Liquid Vims, 40 Conqueror's Periapts, a Godsbane (just in case), a Maker's Finger (just in case), a Wakestone (just in case), and my dragonkin tears because I'm too lazy to put them away. Plus any equipment I'm planning on dragonforging. Put all that together and I'm still sitting at Light encumbrance when I'm fighting Ur (and perhaps Very Light by the time I'm done).
I go in dozen vims, one mitridate (poison already swallowed), 32 conq periapts and 32 demon's, a wakestone and 30 mushrooms (just in case). With just gear I am wearing (no swapping) that puts me high average - heavy depending what armor I am df'ing...These last 2 gens I only used 2-3 vim's total.
FYI, I was going in to contribute to bringing him dowm, and first time he was already in GP - my post was a short time later (killed him, saved, and then had to cross the room to my computer to make the announcement ) - so my announcement was not the exact 'Start of GP' time. --for those who were concerned about the length of GP.