I am unashamed to say that I liked playing summoner-types in D&D 3.x, especially with some of the really abusive combinations possible with 3rd-party materials.
In my defense, I always brought my monster cards, and own minis, so I was prepared. I always prepared my action list in advance, and was usually one of the fastest turns at the table, despite sometimes having as many as eight critters and sixteen attacks. Heh. Yeah, I love me them minions.
Which is probably why Summon Monster has disappeared from the 5e PHB. After all, 5e is intended to streamline play, and be a less-complicated experience.
But, whatever. I'm not alone in feeling the gap, and this looks like a pretty fun and creative way to fill the void.