Leveling Limit?

Yes, I usually stop at Level 40 /._.\

I've never went past 31.5 . If I have any Pokemon higher than that, it's because they were weather boosted catches

As far as the meter goes.

100 Tyranitar at 40.
93 Kyogre at 36 (so far)
96 Raikou at 38, another 93 Raikou at 31
98 Exeggutor at 35.5
96; 93; 93 Dragonites at 35.5
96 Zapdos at 33.5
96; 91 Lugias at 32
Three Gyarados at 35
Two 96 Moltres at 31
100 Gardevoir at 32 (so far).

Caught a 15a/11/15 Mewtwo today, started the long road to max it.

Took a boosted Rayquaza to 30 already. Will take another to 35 if I finally get a 98 or 100.

I usually stall out on stuff I start, but with most others just catch and evolve high boosted (Sceptiles, Venusaurs, Walrein, Vileplumes, Charizard, Machamp, etc).

After 31, I need a specific reason to power up, usually a break point or bulk point vs a raid boss that I am about to fight.

Max. I find bulkpoints/breakpoints useless since they sacrifice an important, permanent resource investment for a temporary scenario.

Additionally, most bosses can be taken care of by weather boosted lv 35s. Anything that requires more investment than that should really be something that I max out, unless I were trying to make some awesome video of soloing ray or something, which I am not.

Before gen3 and weather, my limit was lv31, I had a wide range of specialist and a huge chunk of stardust. After gen 3 dropped and max level wild catch increased to 35, I find myself powering my most meta ones to 36 mostly legendaries, tyranitar and a few loved ones like Sceptile and good old Venusaur

Nowadays I don't power them up at all unless I'm taking them to 40. Weatherboost has changed the game a lot.

I play to max out Pokemon. Never hold on to dust.

There are three scenarios in the current meta for powering up. 1) To put together a decent squad to attack the boss of the month, or some three tier raid you want to solo. In this scenario level 30 is a good rule of thumb for a squad of whatever (2*90% > 1*100%), and it is much cheaper to power to 30 than 40. 2) Holding gyms 15 minutes, or so, before raids. I have one level 40 blissey for this. In a medium density area, this is all I need. I can get coins from random junk. I may pump up a chansey in case I am the second in the raid gym. 3) Gym clearance allows a squad of six. So, I have taken most of my gym clearance squad to level 40, and try to get each member to take specific roles that can address any gym I might encounter.

All my attackers are level 30.

Just hatched a 98% Machop; the first attacker that I would consider maxing out.