...Anyone think either of the aforementioned weapons are actually WORTH anything, given the fact that HV weapons are rather weak and so is the 5-7C?

One bit of merit to the 5-7C that I would include in my personal errata: Makes its bullets essentially always APDS, as the r/l 5-7 can naturally break through kevlar.

Opinions/thoughts/comments?

The HV weapons are nice, I've been told, when mounted on a small turret. As personal weapons, they're less than stellar. The 5-7C is just a bad deal all around, and that house rule, or some variant of it, seems a popular one. Personally, I don't give it any special bonuses-- the current 5-7 is very good against kevlar, but there are numerous indications that SR armor is something fairly different from kevlar, or at least modern kevlar. Could go either way, depending on the game.

I'm what is those characters mean in laymans terms?

HV weapons are great for suppressive fire. characters who can use HV weapons effectively in normal combat are the exception rather than the rule, though.

is it HV as in the weapons with double rate of fire?
Where are the stats for the 5-7c?

The 5-7C's stats are in Cannon Companion.

...And a street sam with a pair of Super Mach's, ambidexterity, and some good skill
is easily a force to be reckoned with, methinks. Too bad my rigger/sam/gun bunny has to default to use SMGs...I gave him Pistols 6, Assault Rifles 5, Shotguns 5, and Launch Weapons 4.