Go OEM or DieHard AGM for replacement battery on MK7.5?

My 7.5 is in for a recall and the dealer is saying the battery failed their test (it has not yet shown any symptoms of being weak/bad even during a harsh upper Midwest winter).

Their replacement/out the door price is $259 which is exactly what a DieHard AGM unit is from Advance Auto Parts. Is the factory battery also AGM? If not, it seems wise to go with the “upgrade”.

Changing it myself is a non-issue. Also have access to VCDS if any coding/adjustment is needed.