Yes, BLAMs are significantly better sounding/quality, especially when paired with a proper amplifier. They are 2 ohm and just sound awesome for the price.
I had the Polk speakers in my jeep and they were great back in 2012, yes 2012, when these BLAM speakers were not around.
BLAMs are the same price as Polk. These BLAM relax are, their high end stuff costs more than our TJs.
Do you know of any US sellers that sell them? My bank doesn't let me do international purchases without contacting them and the link you sent is a UK website.