Which one is better, I like them both, but I like the mega stones a lot as they make ya Pokémon look very badass the Z crystals are fun, but they only last for 1 turn and ya can only do it once. I know its also so for the mega stones, but at least ya have the mega form for the whole battle while the z crystal isn't. a silly but funny dance move, a quick badass attack and than its done. so what ya think?
Honestly it depends on the circumstance. Although I usually prefer to use mega evolution, some megas are just bad. Also not every Pokémon can mega evolve, while every one of them ca use a z-move. Either way, they are fun to use and I hope new versions of both come out in the future.
Mega stones for sure, I like the alternate forms of Pokémon a lot more than just a plain Z-move. It feels more creative and more like a touching evolution even if it lasts like 2 minutes or so.
Z-crystals. I am very biased on this. I used megas only because of them ALWAYS being used on me and i had to even out my mono teams. I find that one use on a super powerful weapon is better then a chain saw that is super powered and is cutting everybody down unfairly. Its just me probably but tanking a z-move competitively to a primal groudon just seems better in battle. From a the stand point of the moves always looking the same for z-moves and they are longer, yeah its annoying but at least i only have to worry about it happening once and then i can progress to worrying about the rest of my team. No only this but the pictures in the crystals are adorable. and the dances always made me chuckle. XD; Sorry i always look at things in a competitive view.... ><
This would have to go to Mega Stones. Both are based on a "bond between trainer and Pokémon", but Mega Stones seem to be more effective and speacil. Only certain Pokémon can use them, and they get buffed for an entire match, rather than a single strong hit.
i loved Mega Evolutions because it takes a new twist on an old Pokémon and makes them greater! (Or in some cases, worse) screw z-crystals to hell
I do like Mega Evolutions quite a bit, though I think Z-Crystals are a little more reliable. You can give one to each of your Pokémon and not be completely screwed if your Mega faints (assuming you were leaning on that Pokémon). Personally, I've gotten more use out of Z-Crystals than Megas, though that's probably because XY and ORAS were kinda easy (and you don't get the Mega Stones forever. Seriously. Why is the Houndoom Mega Stone in Y version when Houndoom is X exclusive? That makes no sense whatsoever.) Again, I like them both. I've just found Z-Crystals to be more useful in more occasions.
The fact that Z Moves are limited in use impacts my opinion. You can only use one Z-Move per battle, and it's really annoying when you're in a hurry and the other guy uses a Z Move. Also, I'm biased towards Mawile. There is a Mawilite so I'm going with Mega Evolution.
I like Mega Stones a lot more as the power boost lasts the entire battle. Also, the transformations look so awesome when they turn into their mega forms.
It all depends on the situation and how you use it. Just like megastones, z crystals have a particular niche. It's not how deep you fish, it's how you wiggle your worm.
Mixed feelings. If Megas were consistently amazingly badass transformations like Absol, I would never take another look at Z-Moves. But things like Mega ****ing SLOWBRO ruin it. I HATE Mega Slowbro! ****ING HATE IT! IT'S A PIECE OF WORTHLESS CRAP- Oh. Sorry... I will say some Z-Moves are cool, but Megas stay Megas for the whole battle. So you can either look at your winged archangel of vengeance for the whole battle, or you can look at a Shellder's ass. I will say Z-Moves deserve a spot in the next games, though. Along with better Megas. #MissingNo
Z crystals are much more of a game changer than mega evolution imo. Moves like Extreme Evoboost, Z Belly Drum, Z Splash, Z Conversion, Z Geomancy, and other ridiculously powerful attacks make it so you can essentially get a free KO or huge set up advantage (combine the move with an ability that boosts your stats after a KO and it's even more so devastating).
To answer, it truly does depend on the scenario. If it's a Pokémon where you need to have a long term power than a megastone would be my go to. But in general Z moves help end it with one hit sometimes. Again depends on your strength vs the opponent
I usually end up using neither of them during the main story. And even afterward I just don't feel the need to get them or use them. But if I really had to choose, Mega Stones. I am a huge fan of Metagross and that is the only one I use pretty much.