Just checked the Steinberg download assistant so I could compare the two versions of Absolute.
Result is:
Updates are mainly for the GA5 - 299mb + 31.14gb content (A3 has 7.46gb total)
Halion sonic 3 (I believe this was in Cubase anyway?) 801mb
Prime Cuts - 142mb
Granular Guitars - 2.33gb
Rock Essentials (GA5) 77.77mb
All other plugins/content are identical and the same download size, so no changes at all. No updates for any other plugins.
imho this should really be marketed as a GA5 update NOT an Absolute update. If you look at the cost of Groove Agent 4 I don’t believe the £85 upgrade cost for A4 is justified for existing Absolute users. Would have been better to upgrade the GA for a more reasonable cost.
If you want an accurate precise comparison, open download assistant and switch between A3 and A4
just my thoughts