I had been using the Milwaukee regulators, but over time (les than 2 years), the solenoid began to malfunction, replaced one, malfunctioned again, replaced it again, but could not get it to bubble consistently due to issues with the bubble chamber, the low pressure side of the regulator, and a few other areas I found corroded inside the regulator (hmmm, possibly an issue with the anti siphon check valve???)
I've been using the Gen-X regulator since then (replaced around March of 2006) as a replqacement, but I like it so much that I am replacing the one on the prop system as well (as it seems to be starting the same issues that the first one did, both are/were Milwaukee regulators).
I'll be watching them both though to see if any issues develop, not running bubble chambers on either regulator, relying only on the pH controller (

)