Half-bridge in this group is the Korean Circuit board design. Full-bridge is what is commonly referred to as the Brazilian circuit board design. Used to be the inexpensive go-to watt for dollar amplifiers, until voltage issues came into play and they had significant thermal issues. Much of that has changed as the full bridge amps have evolved. With that evolution, the better ones are starting to cost as much as the others so much of their appeal (watt for dolar) has diminished somewhat. The full bridge amps are about half the size but require much more stable voltage. One of the appeals of the JL is it's regulated power supply, hard to overdrive or break. Unfortunately, it's a bit underpowered in this group.
I generally prefer to run my subs at higher impedances anyway, everything runs cooler, last longer and performance of any amplifier is most efficient and controlling at 4 ohms. You're close at 3 so power is important. I have the H-KO3, running at 4 ohms, 1500 watts to dual 400 watt RMS subs (RMS 800 total). I have the gains tuned accordingly and the amp barely breaks a sweat. THat's just how I prefer to set up my equipment. I'm loud as hell if I want too, but not concerned about extracting every little bit of juice to win some SPL competition.