I honestly think the Blade is meant to be an 18x20. The 16x19 was made by Wilson probably since it is so popular they could make two versions and some people asked for a 16x19 pattern. It is still a relatively light stick and as a result, the spin with an 18x20 pattern is very high due to racquet head speed.
It trumps the Radical Pro by far for me. Far easier to swing and it's just a lighter stick in general. The YT Rad Pro really grabbed me when I first got it, but the SW was 345 (my blades are 331) and bugged my shoulder.