Greetings all, I happened onto your thread and am a long time cat and heli skier who lives in Denver. Hope a newcomer is welcome.
I have not skied with El Diablo/Silverton or SJSC from Creede, but have skied with San Juan Powder out of Purgatory and some others over the past 20 years. My thoughts for what they are worth:
Best steeps and altogether best terrain: Irwin if it reopens
Steeps, least frills: Monarch
Best overall experience, but tends to be moderate pitch: Steamboat (great folks)
Very reliable: San Juan Powder
Okay but more limited in terrain options: Chicago Ridge and Vail (I agree, great folks)
Way expensive, limited terrain: Aspen
As for Heli: I think that the Heli operations in BC are the way to go for greater safety and more heli-friendly terrain. Peaks are 8000 ft rather than 14000, much safer flying and a lot more access. And the dollar is stronger again, so you get a built in discount of 20-25%. Huge variety in prices and type of experience though, so choose carefully.