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
Debra
Debra K
Eros 2Phono amp
BeePre2, Psvane ACME 300b
Kaiju, Linlai Elite 300b
Monamour 2a3 amps various tubes
Sota Sapphire, Pete Riggle Woody Tonearm, Kiseki Purpleheart Cartridge
Rega P6 Ania Pro cartridge
Roon Nucleus
MHDT Labs Orchid DAC
Jager speakers