There's nothing wrong with miracle grow, as long as you buy the right box. It gets a bad rap because a lot of people will put seedlings right into their mg soil, which is preloaded with nutrients. These guys probably then douse the seeds with GH nutes, and their plant dies. Well, a lot of growers use GH successfully, so it must be the miracle grow, right?
If you buy the water-soluble miracle grow, it will work just fine for soil. It's Miracle grow hate arises more from product misuse than product efficacy. As for someone claiming the nutes are too salty: You need to understand that nearly every bottle of nutrients in your hydro store is make up primarily of salts. Look at your fox farm, your GH, your AN, your humboldt, these are all made of salts. Calcium nitrate? salt. Monopotassium phosphate? salt. Potassium nitrate? salt. Zinc sulfate? salt. You get the idea... So to claim that it's much saltier than other nutes isn't exactly correct.
People will overfeed and burn their plants with MG because they add too much of it. This can be avoided if you buy a ppm/EC meter, and can measure how much fertilizer you are actually putting in your water. Or by adding less than the manufacturer recommended dosage.
But MG does sell complete, water soluble nutrients with micros added.
http://www.scotts.com/smg/products/Miracle-Gro/hose_feeder_and_refills/pdf/MGGardenFeeder.pdf
This is the only pic i could find of the guaranteed analysis online, but as you can see, it does include micros, and the NPK ratio of this specific one is 1:2:1 (divide by 15).
They also sell 24-8-16, which is a 3:1:2 ratio. 3:1:2 is the same as DynaGrows foliage pro, and is a good ratio for vegging cannabis. Just because it's cheap and isn't marketed for marijuana doesn't mean it's not a good product. It just needs to be used properly.
It will work fine for soil, just dont go crazy with it