Like what ? MP problems aren't a thing anymore with overgearing (so we'll have to see if it's fixed in the extension or not before complaining again)
focus on DoTs + egis rather than summons ? Well, sorry to say, but it's technically correct, as the SUMMONERS use the essences of divinities to enhance themselves while the INVOKERS use the essences of divinities to unleash hell on their enemies. Though the naming has been a little confusing over the various FF games, because there are summons in each case, thus making the invoker a special case of summoners.
I don't know any "major" concerns about SMN but I'd be happy to learn more about what people are displeased with
