Here are the differences:
Sure Power 1314A: Single sensing, closed current 750mA, Cranking Amps 400A, Continuous Amps 100A
http://www.ase-supply.com/v/vspfiles/downloadables/1314-1315.pdf
Blue Sea 7611: Dual sensing, closed current ~100mA (measured), Cranking Amps > 210A, Continuous Amps 120A
https://www.bluesea.com/products/7611/BatteryLink_Automatic_Charging_Relay_-_12V_24V_DC_120A
Blue Sea 7622: Dual sensing, closed current 13mA, Cranking Amps 1450A, Continuous Amps 500A
https://www.bluesea.com/products/7622/ML-ACR_Automatic_Charging_Relay_with_Manual_Control_-_12V_DC_500A
The only difference you will notice is dual sensing vs single sensing. With either of the Blue Seas models your camper solar will also charge your truck battery. To me, this is a big plus and worth the upgrade. However if you have lithium batteries you need to think carefully about this.
The other differences won't provide a noticeable change in performance. As I mentioned before, the closed current consumption is not a big deal as the relay is only closed while charging, except possibly with the Sure Power as it seems to consume enough to get hot (neither of the Blue Seas do). The amp rating doesn't matter either as they are all well above the ratings of the circuit breaker in the wiring. On price the 7611 and 1314A are about the same price, the 7622 is $100 more.
Sure Power 1314A: Single sensing, closed current 750mA, Cranking Amps 400A, Continuous Amps 100A
http://www.ase-supply.com/v/vspfiles/downloadables/1314-1315.pdf
Blue Sea 7611: Dual sensing, closed current ~100mA (measured), Cranking Amps > 210A, Continuous Amps 120A
https://www.bluesea.com/products/7611/BatteryLink_Automatic_Charging_Relay_-_12V_24V_DC_120A
Blue Sea 7622: Dual sensing, closed current 13mA, Cranking Amps 1450A, Continuous Amps 500A
https://www.bluesea.com/products/7622/ML-ACR_Automatic_Charging_Relay_with_Manual_Control_-_12V_DC_500A
The only difference you will notice is dual sensing vs single sensing. With either of the Blue Seas models your camper solar will also charge your truck battery. To me, this is a big plus and worth the upgrade. However if you have lithium batteries you need to think carefully about this.
The other differences won't provide a noticeable change in performance. As I mentioned before, the closed current consumption is not a big deal as the relay is only closed while charging, except possibly with the Sure Power as it seems to consume enough to get hot (neither of the Blue Seas do). The amp rating doesn't matter either as they are all well above the ratings of the circuit breaker in the wiring. On price the 7611 and 1314A are about the same price, the 7622 is $100 more.