How much of a success rate am I looking at by transferring my 2.4.3 addon settings over to the new 3.0.2 addons?

I ask because I haven't played WoW since August 6th, 2008 and used to update via SVN nearly every other day. However, since my "time off from WoW", 3.0.2 came about and has not only prompted many addon authors to update their addon(s), but also shift to either new structure, new design, new addon architecture, or at the very least a "new version".

An example would be Bartender4, whereas prior to this week I would have been fine using BT3.

Essentially, all I want to know... is how "dirty" would I make a new batch of addon installs if I attempted to transfer settings/setup from old UI addons (like Bt3 to Bt4)?

Would I be better off just trying to rebuild from scratch? I just don't want to run the risk of somehow tainting the otherwise fresh addons with a lack of elbow grease by trying to port over settings files that may contain old/problematic data. Or at least, which ones pose larger risk for error than others.

I look to the community for feedback/guidance regarding this concern because I spent a LOT of time customizing a lot of custom made art panels, custom made frames/borders to fit a specific screen space and a few of the addons listed below were used heavily to achieve the look and function/form I wanted to achieve.

Following is a list of addons that most concern me - of which I'd like to carry over settings (by copying their .lua SavedVariables):

- PitBull (Aug 6th build) to PitBull (Oct 15th build)

- Prat (2?) (Aug 6th build) to Prat 3.0 (Oct 15th build)

- Bartender3 (Aug 6th build) to Bartender4 (Oct 14th build)

- AuldLangSyne (Aug 6th build) to AuldLangSyne (Sept 29th build)