Li Shenron
Legend
I did find that a huge disappointment. Summoning was problematic in 3e, but 4e handled it so well.
I am not familiar with 4e, how did it handle summon monsters spells?
I remember that in 3e Summon Monsters generally slowed the game down because of the increase in number of combatant.
The short duration also wasn't very nice IMO, 1 round/level (IIRC) meant that they were only of minor benefit to a low-level caster, then at low/mid level the duration was close to that of a whole combat (forcing you to keep track of it carefully), and at higher level it became irrelevant. In all cases, the duration didn't prevent the caster to use summoned monsters as trapfinder dummies, but it prevented using them for more creative and less game-breaking uses (messengers, thieves, laborers, creating distractions...).
In 5e I was expecting concentration to be required by summoning spells, rather than having a short duration. This would have allowed more non-combat uses, but at the same time preventing too frequent combat uses.