I feel that in looking for a motor home built between 1999 and 2003, the care, or lack of care it has had over the years, is more important than where it ranks on any "hierarchy list" from when the vehicle was new.
As for the Spirit and Winnie, normally they are at the same level. My 2014 Spirit is at the bottom of Itasca's offerings. Perhaps other years it was a higher level. I have a 2001 Itasca Sundancer, which has an almost identical layout to my Spirit(one has a U shaped dinette - the other booth seating) and that is definitely a step up in features and quality from the Spirit.