Honestly my only main issue with MG soil is the PH, which can be up to 8 in some of the organic products. Sometimes it comes packed with fungus gnats too, which sucks.
I've found MG soil to be EXTREMELY alkaline, with a pH of 8. Also has way too much N for a seedling. I've grown seedlings with excellent results using either perlite, vermiculite, rockwool, or peat moss
If bud tips are drying, maybe check for bud rot? Is there grey fuzz, black dots, or a pretty funky smell near the dry bits? Last time I got bud rot, all of the leaves turned brown, and the colas began drying from the top down.
Paying attention to trichome color is the most important thing you can do. For more of a head high, you want white/cloudy trichomes, whereas for a body high amber is the ticket. Here's a guide with a trichome chart