There is absolutely NO REASON to use Espeon in OU for 2 major reasons. The first of which is that Espeon is completely outclassed Alakazam as a pure Psychic Special Sweeper who possesses the same coverage with higher Special Attack and Speed. Alakazam is better in every aspect with your set. Alakazam additionally has a much better ability than Espeon being Magic Guard. This allows it to be a very solid wallbreaker. Espeon does reflect many of these moves, but it is still outclassed by Magic Guard as an ability. Even if you wanted to use Espeon for its Magic Bounce Ability, it is still outclassed by Hatterene.
Now, let's say that you don't care that Espeon is worse than Alakazam, bring in the lovely Pokemon of the OU tier. Here, you have to deal with a faster Pheremosa that will OHKO you, Weavile that will OHKO you, Spectrier and Dragapault that OHKO among others. See what I'm getting at? Any faster threat that has offensive capabilities will OHKO before you can even get a move off. Because of this, Espeon should never be used in OU, bar any small niche you can find.
You asked for pros and cons, so here you go.
Solid 130 SpA and 110 Spd.
Fun ability in Magic Bounce to disrupt walls like Toxapex as well as Hazard Setters.
Solid check to Urshifu (as long as it isn't scarfed)
Solid STAB and coverage in Psychic, Shadow Ball and Dazzling Gleam
Refer to paragraphs above.