You do realize that the Micro-Condemor is a Bolt Rifle cut down to pistol, right? Lol. Doesn't the Micro modification make it a pistol class weapon? That would remove the Mono-melee attatchment. Overall the players encounter enough Yu'vath and Daemonic enemies to prefer Sanctified weapons whenever they can carry them.
My group includes two Hereteks. The Rogue Trader is an Arch-Heretek with a focus on weapons and keeping his implants discrete. The Explorator is a Factor of the Lathes with a 50 Fellowship and massive social skills. He also tends to keep his implants inobvious. The social fu of the group is almost painful.
For NPC Hereteks, have you used Imperial Robot bodies with Scaracen Wave generators attatched to the Heretek's brain burried within it? Gives him lots of room for extra weapons and systems. Nothing like having dreadnaught class opponents with actual skill and intelligence behind them.