LvL Attacker Past 30?
I know a lot of people dont recommend lvling attackers past 30, unless you have a lot of resources.
So, I have a 100% Jolteon with TS/TB. Ive already lvled it to 34.5, but debating if its worth going further. Eevee candies arent a problem, close to 1k and stardust is at about 900k. My only concern is stardust. I have a lot of other mons I would power up, but Im a bit conservative with my dust.
Answers
Everything may be reworked and changed before Gen3...but my point is that you need to know the exact defence stat of a mon you want to battle to take advantage of the 'floor+1' phenomena.
There is no specific level for any specific mon that will permanently trigger the increase in damage done by flooring against everything.
Some people appear to think that by getting to a specific level with an attacker it will trigger the increase in damage for every mon they face...when in fact it is dependant on the defence level of the mon you are attacking, as much as your own attackers attack stat.
TL/DR Floor damage increase for an attacker is not consistent against all opponents.
As someone who has actually continued to power up and max out all of my attacking team to level 36.5 (I am only a level 35), including a 95.5% IV TS/TB Jolteon, I say it is worthwhile to level past 30 and the difference as one levels higher up is noticeable. And I will continue leveling them up as I level up. Stardust is meant to be used, not stored. I'm pretty sure most of the people who advise against leveling past 30 have never done so and are speaking purely from theory without experience to corroborate their views as to how effective such leveling is or is not.
Obviously, if you can't afford the dust or candy, that is a different story.
Personally, I like maxing out my very favorite mons just because it's fun. That includes a couple of 100%er with great move sets. If you like this Jolteon and use it a lot I would have fun with it an power it as far as you like. Stardust is an infinite resource, as long as you keep playing you get more.