I used the off-site parking for the first time on our April cruise. I talked about it in my trip report (link below, "A Fantasy (Cruise) Come True". Our experience was not a "nightmare", as Sweetpee's was. But it was definitely not the ultra-convenient experience that the DCL lot is. There was a little delay to be driven to the port (not more than 15 minutes), and there was a long delay to be driven back to the lot after disembarkation, which was frustrating. But overall, I think I would probably do it again for the money saved. For our 7-night cruise, the rate was $4.99/day, and I think there were taxes added, but I can't remember. So waiting 45 minutes to save $80 seemed like a fair trade to me.
I can definitely understand why not everyone would feel that way, but I didn't think it was so bad.