The wattage rating of most LED panels doesn't have anything to do with wattage in vs wattage out, sorry to 'come down' on you. lol
Most places (Gotham Hydro/Lighthouse hydro included) get their 'wattage' by multiplying the number of LED's they have by the peak wattage the LED's are capable of. Keep in mind that virtually no one runs LED's at 100% peak power. So, a panel with 200 LED's might end up with a name like; "600W Blackstar LED Panel", but really it has 200, 3W LED's being driven at <2W each, and pulls about 380W, not 600W.
The Blackstar 180 pulls 110W, the Pro-Grow 180 pulls 160-165W, etc., etc., etc.,
There are companies that provide actual draw figures so you can see exactly how much they draw. Area 51, FERO, and California Light Works are a few of the more reputable companies that sell LED's. I have personal experience with A51, they're fantastic with customer service and have the best warranty, hands down. Period.
I own a few Blackstar panels as well, they're not bad, and bang for the buck, they'll grow some bud. They're still not a leading echelon of the LED grow light world....
I agree with EnduroX, most LED's are about 2/3 the equivalent of HPS. 1000W HPS = ~660W LED, ball-park figure.