Weight isn't the only issue -- in fact it's really hardly an issue -- both of these are regularly accepted as "heavy glues" to be used sparingly.
The pros and cons, as I see them:
-- set time: a 5 min Epoxy will set in 5 min, but will take as long as 24h to fully cure -- depends on the brand. HG will be at full strenght once it gets back to ambient.
-- hardness: Epoxy is *typicaly* very rigid, where hot glue will always have a slight rubbery give to it. there are epoxy blends that are softer, but I've yet to see a truly rigid hot glue stick.
-- perminance: Epoxy is forever. Hot glue might not keep it together sitting in the back window of a car on a hot Georgia summer day (dunno about Karnataka, but from lattitude alone, you might have us beat).
-- mess: unmixed resin sticks to *everything* and creates a tacky coat that's hard to clean -- other than the stringy strands and pulling up overflow on a porus surface, once hot glue cools the mess isn't spreading farther as you try to clean.
-- Safety: Hot glue BURNS!!!! and if it's a big glob, it's really hard to get this scalding hot blob away from your skin. It'll easily give a 1st degree and occationaly 2nd degree burns. Epoxy can be toxic, depending on the formulation.
so which is best? depends on what you want to do . . .