If you had planned on using those park passes for every day of your stay anyhow, it may be a good deal for the onsite portion. Disney Deluxe hotels are very nice. If you wanted to stretch your value with park hopper passes (which don't expire), it may not be the deal you'd thought.
Having done both (on/off) many times with a family of 5 (plus guests on some trips) and preferring to spend a few days of our trips relaxing around the pools, this is what I'd consider:
If you'll go from an onsite hotel room to a spacious offsite condo or suite, that's fine. You'd probably really appreciate the added (personal) space at the end of a long trip together! If you'll go from an offsite, decent hotel room to an onsite deluxe resort, that's fine too. You'll enjoy the upgrade in resort amenities. If you'll go between an onsite Disney hotel and an onsite Universal hotel, visit Universal last because they offer FOTL privileges (no waiting in lines), which spoil people!
But if you're planning to go from an onsite, themed, deluxe resort hotel room to an offsite, modest hotel room, then you're in for a real letdown, IMHO. Even if you thought you were prepared. If that's your game plan, see if you can switch your reservations to stay in the ordinary hotel first and move to the deluxe, themed resort second.
This is a pet peeve of mine. Folks on some of these boards tend to compare deluxe onsite resorts with basic offsite hotels, then comment negatively (and rather definitively) about staying offsite. No kidding, if that's the comparison!
FWIW, our family really prefers and enjoys all the deluxe amenities of spacious, luxury condos. These are (by far!) most affordable offsite and we love them!

We don't like to get up early on vacation for EE. We prefer to drive rather than stand in line for crowded, smelly buses. And we really appreciate the inroom jacuzzi, washer/dryer, kitchen, extra bathrooms and TVs. We've done the onsite DVC thing and the themes are nice but don't make or break our vacation. So, offsite timeshares are our choice. YMMV. HTH.
