I thought watts didn't matter when it came to QB, because the PAR is higher and its only PAR that actually matters? I don't get why they claim 2x4flower each light if it isn't true, why Ive been hesistant to get LEDs, seem to be so many false claims.
Watts are a measurement of
consumption, not output. If that's what you mean by "watts don't matter". It is the output of usable energy that's important, whether it's generated by 500w, 1000w, or 2000w. PAR, yes. Maybe watch a few vids on PPF, PPFD, PAR, etc.
They aren't making "false claims". The wattage they list is the actual wattage of the fixture (driver); the wattage +/- a small percentage for the efficiency and other variables.
You're right to be hesitant, there's still quite a bit of bullshit, and there always will be too. Just try and get a grasp on the basics of plant lighting (what they use) and you should be good

People here will help you out.
Three 260 kits is three 240h drivers. If A-type, they output about 5% more than rated, and either way, they pull a little more power than just the driver rating. So, for example 3 x 240w = 720w total (probably closer to 750w)
A wattage recommendation, such as for a given area or footprint is only good for a specific light ("technology"; more specifically, bulb, diode, etc.) 30-35w per sq/ft is the common suggestion for
HLG qbs (or perhaps for the samsung diodes they use). This is because the math has been done to calculate how many watts (of that particular lighting technology) are require to provide a certain level of PAR output (in PPFD).
So when someone says "you need 'x' amount of watts in 'y' footprint/area", it's because (it
should be because) that amount of suggested wattage will provide 'z' (adequate) amount of light energy to the plant (say 700-800 par, depending on spacing and height of course).
You have a 6x7 area, which is 42sq/ft. 42sq/ft x 30w (per sq/ft) = 1260w
The 30-35w per sq/ft recommendation is for flower, with the boards in question.
As always, correct me if I messed up somewhere.
Hope that helps.