I've done this sometimes, I think it's pretty dependent on you being able to fall asleep quickly. Which you can train yourself to do. But it would usually be more of a 3hr/4.5hr split to match with REM cycles. Or just 3&3. I felt fine. If anything I prefer it, but realistically I've found it hard to do while working 9-6. I end up wanting a sleep time in the afternoon.

Sometimes I do 6hrs at night and take a nap on lunch for about 45minutes. This is okay, but hard to do outside of winter as it's too hot to sleep in my car.