So I have played my first game of 10th (sort of, just the "kill everything" game). Invulnerable saves need to be significantly restricted, or reduced to 6+ across the board.

If I fire the Total Terminator Death Brapper at a Terminator, and it goes through, they shouldn't be able to have a 50/50 chance of ignoring it. By all means, give them more wounds, make them cheaper or some other rubbish. Invulnerable saves (as they currently exist) make a mockery of anti-vehicle or anti-elite weapons. It's more likely I will wound a terminator just by firing lots of chaff then by using dedicated anti-everything guns.