I put cointakers in my SM and LOTR (just the inserts) and it had the flickering/ghosting problem so I went with the Ghostbusters from Pinball Life and they look fantastic. Out of my machines I have full insert LEDs in SM, LOTRs and I have a few in the inserts of TZ & T2. I have a color changing LED from Pinball Life in my MB for the record insert in the lower middle and one in my T2 in the Timer Insert by the T2 Head. I really like the board mounted LEDs on the Tron LEs. Those look sharp with being overly bright.

I think if you are doing it for heat reasons the LEDs are fine behind the translite. Otherwise, I don't fell you gain that much and a lot of times people use to bright of LEDs in the backbox and it just doesn't look right. I like the cool white LEDs in the TZ inserts. Just a personal preference. I didn't say you had to like it.