I've seen some similar lists running 4 Elvish Mystic at the low end to ramp faster to Prime Speaker Zegana and/or Angel of Serenity

now I happen to love both of those bomb cards, but I'm not sure the deck is really better with them in it.

Anyone tried this deck either way or just have an opinion on which version is better?

I suggest Prophet of Kruphix it works very well so you don't need to worry about swinging for damage and not having blockers :)

I love that card, but I don't know what I would cut for it. What do you think?

The curve is a bit high already, which makes it more difficult

Cut the two Prime Speaker Zegana they aren't good in this deck.

Also cut the 2 Loxodon Smiter . They are amazing, but not recommended in this deck type

Another option is to remove 1 prime speaker and 3 fathom mages for 4 Prophet of Kruphix if you wanna keep the smiters