I actually think Persist is a great model for buff spells in general, especially if it was combined into the spell itself, 5e slot scaling style. You transition from but spells as an in the moment expenditure, to a standardized daily load out as you level up.
My experience with Persist is, if used responsibly, it's a great tool for boosting your party members. My last 3.5 character was a Cloistered Cleric/Radiant Servant of Pelor who used DMM Persist exclusively on party buffs at start of day, then mostly healed and used a Reserve Feat (Fiery Burst, I believe it was) or x/day items from the Magic Item Compendium for the remainder of the day, letting my allies obliterate challenges with boosted numbers.
I felt this was responsible use of the Feats. But your DM still has to be on board, as mine soon found that we were punching well above our weight class consistently, and when he tried to use tactics like Dispelling, found that I'd gotten there first, by acquiring methods to make dispelling my buffs harder. It came to a head when we had to fight a Beholder, and found that, stripped of my buffs, the other PC's were actually pretty subpar, leading to a damned if you do, damned if you don't scenario.
Which had been my point the entire time, to shore up the other party members so they could basically do whatever they wanted. But if even that caused problems, I shudder to think of what would have happened if my allies had been actual optimizers- for example, I had one buff in particular that granted a larger bonus to other worshipers of my God. Every time I cast it, I jokingly asked if anyone cared to convert. They never did, but an optimized group would certainly do so (opening up the use of a healing spell that would be more efficient if used on other faithful).
So whether or not DMM and/or Persist is good for an individual campaign is kind of up in the air. It was fun at first for me, until I saw the DM struggling, without me doing anything goofy like Divine Power+Righteous Might on top of it.
That having been said, I believe the following things are true:
*Buffing your melee is a good use of magic. You should want your casters to buff other players, to make the game more fun for them, and prevent the casters from using the true painful spells, like hard control which turns every fight into "and my monster does nothing. Pass.". Or always having those defensive/utility spells on tap that everyone complains so much about, like Shield or Silvery Barbs in 5e.
*Buffing should be less painful- the current paradigm of useless buff durations where they might last for more than one combat, but generally won't, and you don't often have time to buff before combat, meaning your first turn each fight is throwing on a buff for your allies- I don't mind this, but I know a lot of players don't like this style of play, preferring to go in there and do their own things.
*Buffing should be worth your time. This is related to the first point, but if you look at how buff spells are constantly being nerfed as the game advances, you go from say, 3.5 Enlarge which was a pretty much must-have due to the advantages of bigger damage dice and reach, to 5e Enlarge, which eats up a caster's concentration in exchange for +1d4 damage on all weapon attacks as a SECOND level spell, or how 3.5 Haste buffed the whole party, and 5e Haste affects one guy, eats up concentration, and if you lose concentration, debuffs the target's next turn...blah.
Generally, I feel that a few patches could fix this. First, perhaps each character has "buff slots" analogous to attunements in 5e, which caps the total number of buff spells on them based on their level. Two, these buffs can be cast and "suspended", doing nothing, until activated by the caster. This lets you prebuff without any fuss, and lets you conserve durations.
Alternately, if you want to add 5e concentration to the game, perhaps make a rule where the TARGET of a buff becomes responsible for maintaining the concentration on it, leaving the caster free to do other things.