Depends what else you use on your team. One can't really compare them anyway, as they do different things - e.g. Espeon is a fast Special Attacker/passer, while Umbreon is a Wall. Depends how you use them and all.
Vaperon is ok, but gets Water Gun as the best water move (no surf TM), until Hydro Pump... Fleareon suffers a tad for high attack but lack of attacking moves (but some nice specials... ?), Jolteon good for helping to catch (Thunderwave) for the others.
So, it doesn't matter, as long as you don't repeat similar Pokemon and/or weaknesses in your team.