Hi Bob
I've just replied to Sue's very similar question about Red v Silver v Gold on her separate thread. As I said, I can't give a view on Silver because it wasn't around back then but in my view, Gold was well worth it.
The extra days on Vancouver Island weren't an add on so I think the itinerary may have changed slightly earlier on. I think we did a night in Vancouver, then over to Victoria for two nights before at least one more back on the mainland (where those who where doing the Alaskan cruise add-on that was available at the time left us). We also had a couple of nights each in both Banff and Jasper.
I'm a bit jealous because I'd love to do it again (but I'd probably give the Capillano Bridge a miss this time.....been there, done that, almost lost my breakfast.....) Tip - I can recommend the sea food chowder in the bar at the Lake Louise Fairmont and, at all costs ask your TM if you can stop off at Bow Lake on your way through the Ice Field Parkway. It's not always an automatic stop but, again in my humble opinion, it's got some of the best photo opportunities of the trip. (If Brian Croft is your TM, he'll definitely take you there because it's one of his favourites too!)
Let me know if you have any other questions
All the best
Mandy