I feel like tinkering is part of the hobby so I see the attraction to modding. I added the Backalley Temples to my Ripleys and I think it looks like it just belongs and is way better than the bent plastic temples that it came with. Also added the Bigfoot sign which goes well with the theme and makes it more apparent where that mode is. Hard to see without the sign. Probably all I'm doing. Though mine came with some good looking color matched leds and the tombstone stickers. May do a color DMD at some point though I think there are other titles that benefit more.
I'm a live and let live kind of guy so do what you want to your machine. I do like the red smoke witch WOZ upgrade, Tron arcade machine and the Jurassic Park gate and T Rex upgrades. They look like they belong from the factory.