ive been looking for a straight answer i got a 300watt led spectrum and the strain is og kush doesbthis strain good for led or is cfl better for it and by the way thanks ilgm for the strong seeds these are the best plants ive had yet and they just started veg stage and they are doing great but i wanna usebled for the duration of the grow
It really hard to get a straight answer to whether or not an LED system is good. Some are very good but very expensive, way over priced in my opinion.
There are systems that can nearly half the cost of your electric bill, for example a 350 watt system that will produce as well as a 600 watt HPS and not to mention the electricity costs you’ll save on expensive venting systems to control the heat of a HID, but these lights will usually cost you around a thousand dollars USD.
If you do a lot of research you might be able to find an equivalent off brand system for around $400 USD that will do as good, but you really need to know what you are looking for to meet the performance of the name brand system.
In the very long run the LED system will pay for itself in electrical bill savings and the fact that the LED system will last much longer than HID light bulbs or high output fluorescent lights. But I can’t necessarily recommend them for beginning growers unless you really want to do the thorough research and take a gamble on an off brand or pay the high prices to get started with a well known brand with a good reputation.
So far the only systems I can recommend, but I can not recommend the prices, are the advanced LED systems or black dog led systems, and maybe the California light works LEDs.
In the end; I find the answer to this question to simply be: HID lamps are proven over time to be the best lighting for indoor growing.
On the other hand; LED lighting has come a long way in just a few years. It has always been, and still is expensive compared to HID. There is an arguent that LED runs much cooler, and is less expensive in regards to your electric bill. I have not found HID to be too expensive, in relation to yield, and quality of yield.
With the influx, and market flooding of digital lamps; I personally believe that Digital HID lamps are the best. They run cool, do not use too much electricity, and are really inexpensive! 
IMO Peace
I’m trying leds and for veg and early flower I think they might be okay but for buds worth while I need more light so I’m putting a hps in flower room and led in veg.
My pure indica did much better than sativas and produced dense buds golf-ball sized.Sativas were very airy.Both potent,good taste but I’m switching to hps in flower room.
When my plant started reaching for a bright 26watt cfl light even though they were directly under leds I had a feeling leds are being heavily pushed in the market.
Something to keep in mind, a low wattage CFL that is very close will seem brighter to a plant than even a high wattage HPS that is too far away, that darn inverse square law of physics again. I’m not sure the overall arrangement of your setup under the mars LED system you had with the cfl nearby, but the fact that it was closer could make all the difference in the world. Also the problem with a poorly designed LED that is using mostly red and blue leds only, is some of the other colors that are present in white light is desirable to a plant and that can also cause a plant to want to lean towards something that is providing a better spectrum overall. A lot of newer LED systems are using a good mix of white LEDs as well to counter this problem. Sorry but the really cheap LED systems made by mars and some others just will not give you better performance than T5 fluorescents. Gotta go with one of the big boys like Advanced LED, Black Dog or California Light works to get a good LED system.
One of the reasons I have moved away from small cfls, is the shape and awkward placement of most systems. I did home made systems for the 1st 2-3 years, that I grew. I also invested in different HID lamps and systems; Including, building 3 different 1000 watt systems at home.
In the end, you really have to judge what is your ceiling on cost, and what is the best way to acheive your goal.
We all wish you the best in your growing endeavor. 
Peace