I've taken all of those classes.... 2G03 is pretty easy if you put the work in. I'm retaking it now and appreciating it more compared to some 3rd year economics classes (cough3M03cough). Aswani is a pretty good prof, he's hard to understand sometimes but he teaches the material pretty well and his online notes are more organized than other classes I've had.
I know people who have taken 2GG3 as an elective and pulled off a 12 with a bit of work; I fared pretty well too. Bruce is a pretty sweet prof if you get him. It's the same textbook as 2G03 too so the material isn't very different.
2H03 and 2HH3 are a little different... I thought 2H03 was SO hard but it was also a lot of theory(not my forte) plus that exam was such a piece of crap, Khan's 2J03 exam that year was definitely not as hard.
2HH3 is a lot of calculus so you shouldn't have a problem there... I think I had Letendre. He was a good prof - really organized.