This is tough to answer, as the available dining times impact your show times.
For the 5 PM show, you can dine after the show...which allows you to make sure you've allowed adequate time to stake out a good spot for illuminations. It's daylight.... Can't get the full effect of all the stage lighting, which in the evening is simply beautiful. Yes the march in holding candles, but the lighting on stage during the performance is the real treat!
The 6:45 (I think that's the time?) show is great because it's dark..downside is, they generally advise you to eat AFTER the show because you can't eat at 5 or 5:30 and get to the show for 6:45... You might if you decided to dine in Morroco, japan or France, the closes to the CP dinner package line. I'd avoid places like Canada, Mexico, etc. as that's a hike back to the show if you're running late. If you dine after the show..chances are you're finishing just as illuminations is starting, which impacts your ability to get a good spot for the show.
the 8:15 show... We like this show...we eat early (5:30 / 6) have plenty of time to make it to the show line to ensure we will get the seats we want. (we normally wait in line about 30-45 minutes) However, this gets out around 9 PM...Illuminations will begin at 9:30..so you will have 1/2 hour to find a good spot..you need to plan to walk AWAY from the CP area, as it will be a MOB scene.
So, as you can see, there are pros and cons to all of these times when trying to see CP, Illuminations and Dine! If you're not doing the dinner package...do the 6:45 PM show..that will give you more than enough time to stake out a good viewing spot for illuminations.
Enjoy! We just made our CP reservations yesterday!
Peggy Sue