I am just an inexperienced grower sharing my personal experience.
I grew my first two grows with Masterblend, and I thought both went well considering what a Noob I am.
On my third grow I ran into problems, the plant turned yellow/light green on me about 35 days into veg.
I reached out on here for help, and turns out I had a K (potassium) excess. The Masterblend is a 4-18-38 formula, and I was unable to lower the K to correct my trouble. (this my have all been strain related, as the first two grows I did not experience this)
I ordered Jack's 5-12-26 and have changed over to it, in just 3 days I have seen noted improvement.
I may well be able to use the Masterblend during flowering when a higher K should not cause problems.
I have Zero experience with Maxigrow, so no help there.
Good Luck,
WillieP