Depends on what you value for your vacation. We have done both and it depends on what you want.
If it was a choice between the econolodge and a value resort I would go with the value. I think the best value from onsite is at the low end. You get Disney service for a small premium vs. off site cheap motels.
If you want space then a timeshare or house offer much better value for the money than on site resorts.
We spend most nights in our timeshare. Some considerations:
Space- We prefer having 1100 sf with a full kitchen and WD. We like to cook to save money and do laundry to save packing and going home with dirty clothes. I also do not consider it a vacation unless I have a king sized bed behind locked doors where I can snuggle with Wuv Tigger
Transportation- We have annual passes so parking is free. Some people claim driving is confusing, but it is much easier than my daily commute. We are never more than a 15 minute drive from the parking lot and probably beat bus transportation if you have to wait for more than 2 buses. I did enjoy walking from the Contemporary resort, but you pay a big premium for that.
EMH- Many people plan to avoid EMH days. I think the benefit is overated, but the new evening hours may tip the scale back towards onsite. If we want early we book a PS in the park prior to opening time and it seems to serve the same purpose.
Magic- Very subjective. Magic to me is going 4 weeks in nicer accomodations for the cost of one week at a deluxe resort. We find the magic at the parks. Some things are nice like wakeup calls, bedtime stories, cartoons in the lobby, etc. but most can be replaced for a fraction of the cost.
I do feel that some resorts are worth staying at because they are unique. I really loved AKL and will go back again. It was just so cool sitting on my balcony watching the animals while drinking my morning coffee. I also did CR because I always wanted to stay where the train went through. The MK view of the castle changing colors was spectacular. We are trying WL for 2 nights next month. These experiences are nice, but not cheap. You would probably have to pay me to spend a week in a 260sf hotel room with my kids - no magic there regardless of the location.