So are people splashing their dust into mons now or whats going on?

That was my plan but now with the new system I really don't see the point of powering up defenders, it's just not worth it anymore.
Also it seems like stardust is even more rare than before.

I will just wait and if I will need stromger attackers for the (solo) raids I will power them up.

I maxed out a Steelix for the hell of it. Is ranked as a good defender and I have maxed out a ton of attackers. Some good attackers like dragonite appear to lose motivation fast.... or that's my experience at least.

But I agree dust is best spent on attackers. I have a feeling best defensive movesets are a lot less important/valuable now.

I'm thinking maxing out best moveset/top tier attackers is the way to go.

I will wait a couple of weeks in order to the gym raids be released everywhere and for all players to see if they make some adjustment because right now dust is even more limited than before and don't want to spend the hard earned one on a mon that will sit in a gym for anything between 10mins-2hours and come back with 0-2 coins and no dust at all...