Jolteon
Which one to power up
Jolteon iv91 cp 1619 lvl 21 A15D13S13
Jolteon iv89 cp 2081 lvl 27A15D10S15
Both with TS/TB ill ask because of ADS and dust to spend im lvl 32 right now
Answers
I really like using my maxed out Jolteon, so without knowing your Stardust situation and how easy you can replenish it I'd say go for it.
What's your Eevee situation like by you? Could you possibly but some time and try and get a better Eevee/Jolteon IV wise? How important is IV to you?
For me personally I'd rather power up the higher IV even if that means spending more dust because I personally just hyper focus on that percentage.
First: IV aside, what are your attacks? My Jolteon attacks total 105 (thunder shock = 5 and thunder = 100). I have 11 Jolteons with 105. Their CP & IV vary. My Jolteons take down Pokémon weak to electric ... 1800 CP takes down 2800 CP. Power up to raise your HP/stamina if your Jolteons have this move attack set. Just my opinion... I've won over 800 battles since I began battling this September... Jolteons are my little Generals.