We have been staying primarily off site since they started the daily room checks/invasions, so take my opinion with that grain of salt. Consider the perks you consider the most important, and whether those perks are currently available. If not, my opinion it drops to price.
We have stayed both off and on site since they re-opened last month. We stayed onsite to get the park reservations we wanted. Park reservations are divided into 3 - Annual Passholders; Resort Guests, and Regular ticketholders. If you are an AP, you can only hold 3 park ressies at a time, and HS is booked on weekends through September, with everything but Epcot booked most other days. They did nudge a few August resort and regular reservations towards AP, but they haven't done it often enough to count on getting in. If you are staying longer than 3 days, you really need to stay onsite to ensure that you get to go to a park each day that you want. If you are a regular ticket holder, you can stay onsite or offsite as long as you book a week or so in advance. I have only seen HS booked occassionally for regular ticketholders, and I think just the first few days they were open for resort guests. Otherwise, park reservations are wide open for resort guests.
For onsite "resort guest" status for park reservations, ALL onsite hotels count. Meaning you could be staying at the Contemporary, or at the Holiday Inn by Disney Springs. It takes about 24 hours after you book a Disney Springs partner hotel before it gets into their system so you can make park reservations, but they do work. They do have parking fees and resort fees, but Disney hotels have parking fees too. The Disney Springs hotels do not currently have bus or shuttles, so you would need a car, or walk to DS to catch a bus there.
