Bloodhound is my favourite, but I do have the sapmi approach to warfare, if the enemy can't see or find you, you won't get killed.
He is imo the best character to play solo with. I wish the L1 useless scanner device, was replaced by a technological shock taser that would stun enemies for 5-10 secs (depending on their shield), and unable them to alert their team during that time. It would make solo vs teams more fair. It would make Bloodhound a really intimidating threat, despice his noises.. And perhaps it could be used to place a stun trap. Bloodhound falls short because of the very limited scanner ability. At least make the range much longer, the colors less confusing and the enemies visible for a longer period.