Comparing Accurip from old download vs new CD rip (which version do I keep) ?

[SumGuy]

I've been ripping my CD collection using EAC V1.8 with a SONY DVD RW DRU-510A.

I have a master collection on a NAS. In some cases I have an old download (from a file-locker) of the same CD. I'm wondering which version to keep on the NAS (both are flac). Will the Accurip logs tell me which version is more "accurate" ?

For example, here's the log output from the old download:

===============
V0.99 prebeta 4, PLEXTOR CD-R, May 2008

Track 1
Filename C:\My Rip\01 - Santiago.wav
Pre-gap length 0:00:02.00
Peak level 97.0 %
Track quality 99.9 %
Test CRC C5D3C75E
Copy CRC C5D3C75E
Accurately ripped (confidence 3) [EBCB57DA]
Copy OK
=============

Here's my rip:

============
Track 1
Filename C:\music\ripped\01 Santiago.wav
Peak level 97.0 %
Extraction speed 12.2 X
Track quality 99.9 %
Copy CRC 4DAD2CC5
Accurately ripped (confidence 17) [226FA38F] (AR v2)
Copy OK
===========

These tracks are about 26 mb, but they differ in size by about 140 kb.

Maybe the source CD's are not identical (identical version, pressing or release)? But if they were, would / should the CRC's match?

I have to decide if I'm going to copy my flac files over to the NAS and over-write the files that are there, for these cases where I have duplicates. Can I make this decision based on the EAC logs, and how exactly do I go about understanding these confidence numbers?

[Spoon]

They are both accurate, 100%

Only need a confidence of 1 or more.