I've seen the bad mouthing of the Mars lights as well. Id like two like you have. I think you'll be pleasantly surprised. Maybe it was their older lights people didn't like, I don't know? But I can tell you this, I've sure seen a lot of people using them, and with good results. A lot of the negative comments come from veteran growers that run high-end equipment , not everyone can $1k or several thousands on lights. For that matter not everyone wants to spend that for a hobby even if money isn't an issue. And yes, I was shocked like you at how much some leds and a driver can cost!? Wtf?!
Two of those lights in a 4x4 tent should give you good results IMO. I'll sub in on your journal if you have one. I've got one going, I'm only 2 1/2 weeks in and half have started to grow, the others half are still lagging behind. And I'm also just going to do some light LST. I'd like to do more, topping, quadlinning? looks cool, etc.. But I'm afraid to mess up my plants. Maybe next grow. Good luck bud!