[eridius]

I've had semi-transparent terminal windows going on many years now. I keep them 80% opaque in the foreground, and drop it down to 75% opaque for inactive windows. I also apply a nice blur effect to the background (with the active window having a higher blur amount). It's really nice; lets me see what's behind the window, without detracting from the readability of the terminal itself.

Transparency without blur might be problematic though.

[__david__]

Blur is absolutely the key to transparency. I've found it's a balance: you can go for less blur, but you have to make the window more opaque. With more blur you can go more transparent with the same amount of readability/non-distraction.