Cb and Bob seem to be very happy with them, so I would venture to say that they’re solid lights for the money.
The one thing that would concern me, is that they aren’t going to outperform your 600 watt hid by much, if at all. That being said, I’m somewhere between saying to scoop them up, and maybe trying to save a little more cash.
Let me explain, just so we’re on the same page. LED can and does perform higher on a watt for watt level with hid lighting, however it’s not magic. It’s simply taking a more efficient light source and the benefits of growing under a “full spectrum” light, which is generally easier especially for beginners. But there is no specific ratio that applies to every led. The more efficient your led is, the less power you’ll need to be competitive with hid. However the more efficient the leds get, the price starts to go up comparatively. If you’re looking for 1000 watt hid performance, that’s going to take probabably 550-600 watts of the top leds available. You’re probably looking at $800 minimum for that kind of fixture. If you venture into the diy world, probably $600 give or take. I know, probably not what you wanted to hear.
So back to the light that @bob31 and @Countryboyjvd1971 recommended. The price per performance seems to be pretty good. My understanding is that 400 watt model is about 100 watts actual per cob. That’s pushed a little harder than the average cob which will probably take a little efficiency hit. But it also keeps the cost per watt down. Those guys can probably comment more on performance from experience. Based on the numbers, I would figure about 2 of them to be competitive with your 600 hid, and 3 of them would probably be just a smidge lower than a 1000 watt hid. The obvious benefit with going with 3 of these over a single 1000 would be the ability to spread them out a little.
I’m all for saving some money at whatever expense. But I just don’t see 2 of them providing any better performance than what you have. 3 would be a different story, is that an option? Otherwise we can maybe see if there is a different bulb for your 600 that may provide a little better performance.