I started out with an Iwata NEO, then graduated to an Eclipse (HP-CS). But early on with the Eclipse I damaged it. Instead of replacing parts, I took the opportunity to try other airbrushes.
I tried badger, off-brand, Harder and Steenbeck, and a Mr Hobby model that I forgot the name of. I didn't like any of them and now I am back in an Eclipse.
The floating needle seat in the Eclipse is so easy to clean. And the airbrush has been trouble free. I can't help but wonder if your issues are user caused.
How are you disassmbling it?
How are you reassembling it?
What tools are you using to clean it out?
If I paint with a lacquer, between colors I run straight lacquer thinner through it to clean it out. I hold my finger over the tip to back flush it. Then when I am don painting I disassemble and clean thoroughly.
When I disassemble it, I remove the tip, the piece that holds the needle seat, and the needle seat and put them in a small jar of thinner. Then I remove the needle by pressiing it forward from the rear, and removing it from the tip end of the body.
I am very carefull with the needle, setting it on a soft cloth. And when I clean it I only wipe from the back of the needle towards the tip.
Then I am VERY carefull about inserting the needle in through the back of the back of the airbrush body.
And when reassembling the parts in the tip, I only tighten everything hand tight. I never use tools.
I hope this helps.