Is A Bad IV Mewtwo Worthwhile

You're undervaluing Mewtwo for sure, when it can outperform counters that have super effective type advantage with a neutral damaging moveset that doesn't even have STAB on it's charge move.

Even a crap IV Mewtwo is still going to be one of your top 6 Pokemon to bring to almost any raid.

Lets say you're "unfortunate" enough to get another Mewtwo after you've powered up this one when most players don't even have one of them, the first one won't become obsolete and therefore is still worth the investment.

At the very least you should take it to level 30.

You will never catch a Mewtwo that is not likely to make much headway in battle.

You better believe if I catch a Mewtwo next Monday I will treasure it no matter what IV's (can't be < 10/10/10) and power it up. Its base stats are just that good.

I feel very privileged to have gotten the pass when many high level pros have not ... and it may be the only one I'll ever get.

A 10/10/10 Mewtwo is significantly better than a perfect Alakazam or Espeon. WORST case scenario, you power him up to 30, get a better one later, switch the first one over to Focus Blast and have a gym-clearing expert. Don't let the perfect be the enemy of the good. The breakpoint differential between an 11 attack and a 15 attack is MAYBE two or three extra power ups, and from what I can gather, there's no breakpoint a 15 can reach that an 11 cannot.

Do it. Enjoy it. You'll use it all the time.

Mine is 11/11/12 (76%), and I maxed it to 40 with zero regrets. I use it daily.

I got the rare 10/10/10 from my first EX raid. Moveset was PC/FB. Although I had been hoarding rare candies in anticipation, I didn't power it up for quite a while, figuring I would get another Mewtwo soon enough (although I did convert around 100 rare candies to Mewtwo candies, just to free up bag space).

Several weeks and no additional EX passes later, I decided to go ahead and take it up to level 30, where it is now. At CP 3276, it is very fun to use as a gym clearer, especially against Blissey and Snorlax. It hits very hard, and focus blast has a great animation. I have absolutely no regrets about powering it up.

Pokemon with very high base stats like Mewtwo, Ho-Oh, and now Groudon, are the least affected by IV's, because the IV score is a smaller percentage of the total stats. A perfect Mewtwo has a max CP of 3982; my 10/10/10 has a max CP of 3822, so still pretty darn high.

I did eventually get another Mewtwo, with 80% IV's (14 attack). I TM'd it to C/SB, and powered it to level 35 (CP 3613), and it is a beast in Machamp, Gengar, and Alakazam raids, not to mention against Mewtwo if I am fortunate to get another EX pass. Definitely no regrets about powering that one up either.

I caught my 1st mewtwo yesterday and it’s 2209 cp 75.6% IV with 12/11/11 wondering what to do but I don’t think I’ll get a second invite too soon and even then if it be under 90% IV again then it would not be an improvement over the one I have now

My only one is an 80% (10/14/12) 2217 CP. I will not break my bare minimum of 91% IV to power something up.
He’s still level 20 and I have not had any problems from not powering him up because my team can handle any Raid Boss without him in the line up. I can still get +3 balls from Raid battles because my line up can carry me through despite not having the best attacker in the game powered up.

I still threw rare candies at it to clear space plus for when I do catch one to meet my requirements to power one up. I get not everyone has one but don’t feel obligated because you FINALLY got one to spend the resources. This game is all about patience. You will get a better one and now will have to spend another 242-245 candies on it depending if you Pinaped it or not to max it out plus the stardust.

My mewtwo is 11/11/10 and I still powered it up to level 30. It's CP is 3295 and it has PC/SB, so will be good in another Mewtwo raid.

My sister got an Ex-pass and caught the Mewtwo. Sadly its IVs were only 13a/15d/14s (not even 100%, and 13 attack? Pfft!) so I told her to wait for a better one and transfer this Mewtwo during a double candy event...

Who am I kidding, I told her that regardless of IVs Mewtwo's awesome (and her IVs are really good)! She's only level 27 and is always out of stardust so it'll take time until she gets that Mewtwo powered up, but she will.

I'd say the worst case scenario isn't that you power this Mewtwo and then get another one, but rather that you decide to wait for a better one and never get another Ex-pass. It's probably the BEST case scenario that you get a better one and then have two Mewtwos to power up.