Not seen these working so personal thoughts, to think about, with your own use needed to be taken into account
whats the pattern like?
135W spots they may be but if the pattern is wrong they could be worse than useless, what penetration do they manage?
LED's do last longer and are more resilient to vibration knocks etc
the posting does say they are for roof bars, so may not be right for driving, they are illegal for road use any way so that may not be an issue, off roading etc they may be OK
They will take less power so you should be able to turn them on and use them without engine running
from the picture I would guess that they are more flood / fog than spot the reflectors will not throw light too far