I have Never Played Heavy Gear Blitz but I have seen a few of my friends play it and it looks fun
I would have to say that it does not look as complicated as Classic Battle Tech from the rules Point of view (Personal Opinion). BUT it is just as fun to play as
40k.
If you like WW2 Look into gear Kreig (Giant Mechs in a WW2 Setting) it is made by the same publisher Dream Pod 9