Between the Mares Line and the SP Line I would choose the SP Line... but between these two regulators I choose the Abyss... I have one and it is a workhorse.... you drop it, kick it, go with it anywhere you like, and it is going to deliver you the same air as always (or the gas you use, I use mine with NITROX most of the time)... Excellent all-around regulator... I've used mine up to 195ft on air, and it is even better than being at 60ft...
Note: I don't reocmmend you do the things I've done to mine described above to your regulator, even though it will survive it... :mean: