While LEDs would last longer and not require as much in power, I personally think the signs would look more impressive, and true to "prototype" with them outlined with the EL. More old school neon-ish. YMMV
In my experience, trying to use micro-LED lighting to simulate neon signs doesn't work very well. Too many "hot spots" even when I used white plastic diffusers. The light is just too concentrated, and wiring up those tiny little LED's under extreme magnification is wearing me out. Not fun.
My EL signs look much closer to real neon. I've built (and still use) some LED-equipped signs that are supposed to represent neon and while they're okay, the EL panels' uniform, all-around glow looks much better and they're pretty quick to build. I guess I'm used to working with them by now.
But Miller engineering also makes some nice miniature fluorescent tubes with power supplies that seem to last forever. I use them in larger sign applications like theater marquees and rooftop billboards. My Pantages Theater in my Los Angeles cityscape uses these to great effect (also seen in day and night shots in a back issue of N-Scale magazine.)
I'm not an N-Trak operator so I don't use the lighting systems heavily. For a home layout, I think EL panels are very useful and have all the lifespan the average model railroader will need assuming he doesn't run night operations constantly.
If and when I reach the 400 hour half life of these panels, I'll let you know what happens. For all I know, my own"half-life" may not get me to that point!
