I built a tubelab SE some time ago and it was a very nice sounding amp, though as Doc said it's final sonic characteristics will depend on what other components you use. I used Electra-print iron and it sounded very nice. I have not heard a Kaiju to compare, but compared to the other BH amps I have built, the BH amps sound superior to my ears. The BH products sound more detailed and immersive to me.
I have since cannibalized the TubeLab amps for other projects