I am I the only 10.10.4 users with 2 screens who is incredibly irritated by the various regressions and bugs Apple introduced in terms of window position?
What problems do you have? I've seen none in my two-monitor setup.
The only irritation is a long-standing one with Lightroom. I have the grid display on my secondary monitor. If LR is running and that monitor goes into power save mode, as it does, LR will sometimes move the grid display into a small window on the main screen, while keeping it active on the second display as well. Hitting shift-g twice fixes it, but it's annoying. It pre-dates 10.10, though: goes all the way back to LR4.
There's a handy little add-on called Moom, which deals quite nicely with window movements. It's particularly useful when I use my laptop without a second monitor, then return to using a second monitor. It was pretty cheap.
Jeremy