When Guildpact was new, I was fortunate to be
able to trade for no less than three Giant
Solifuges within just a couple of weeks of the
pre-release. Since Gruul was my favorite
FNM deck of that time, I played with them for
months and months until they had almost as much
wear as some of the Revised duals you see making
the rounds now. There were few situations where
they were bad. They punished control decks for
tapping out to cast Wrath of God, and they were
all but guaranteed to be able to block against
other aggro decks (the odd Cruel Edict aside).
There's no real reason this guy shouldn't be
played in any setting that cares about efficient
creatures. Bloodbraid Elf may deliver card
advantage, but she's both banned in Modern and
far from unsolvable. And I never heard
of anybody actually making the sometimes-alleged
sad face about not being able to target
beneficial cards on a creature with shroud.
Anybody who's ever seen a card like Putrefy will
realize that shroud is an advantage, not a
disadvantage. Besides, there'd be no way to
balance this card and leave it usable if it had
hexproof!