@dreas - I have have Blue Jeans Cable 10AWG speaker cables and have been very happy with them. Like you, I really like the ultrasonic welded connections. I have not compared them anything “high end” but they seem to do pretty well.
I had BJC LC-1 interconnects and found Audioquest Chicago to be better in my system. It wasn’t a subtle difference and given the price difference I’d go with AQ over BJC for unbalanced interconnects.
I now have a Morrow Audio balanced interconnect and am very happy with them. Their marketing definitely is annoying. I emailed them to poke at it a bit. It’s a very intentional strategy that’s working for them. In short, people like sales so that’s the approach they have taken. A little too much like Wilsons Leather!