But.... it's not a choice between a lamp post and a desk, since you can't swap a light object token for a lamp post. In the hierarchy of light 3-D objects, the desk is certainly up there.

Like szude said, 3-d objects are legal in PR and Marquee events (and sealed events in general), special objects that come from boosters other than the boxes you opened for the tournament are legal.

The Indoor/Outdoor adventure pack and danger Room objects are allowed. The Laser Turret, Meteorite, etc. are not. Unless it's a 2-d object you pulled from your booster (although Origin has none of those.)

Excellent point. Choice of special objects is always something to tailor to the actual situation, and who knows if you'll get to draw a heavy object, or maybe you draw all heavies. You've got to be able to adapt.

Thinking you cannot use 3-D objects in a sealed tournament is incorrect. The Heroclix tournament rules state:

1.5.1 Objects
Unless otherwise specified by the scenario, all sanctioned HeroClix games must use six object tokens. 3-D objects are legal for all sanctioned HeroClix games and may be substituted for object tokens of the
appropriate type per the 3-D object rules.