You mean Saratoga versus nuGalactica? Saratoga. They're about equal in fighter and logistical strength but Saratoga has a greater array of offensive anti-ship weapons, while nuGalactica, without her planes and Raptors, is mainly a defensive platform. The exception is her tactical nukes, which we know she has but she never actually used on screen.
I think you're wrong.. Galactica (and Pegasus) have taken on Cylon Basestars one on one.. they have main guns and they are powerful, easily taking out a Basestar with 2-3 direct hits.
Not quite two or three shots. When they took on the Cylon fleet while attacking the Resurrection ship they bombarded their baseship targets with hundreds of rounds. Still, yes, the rate and volume of fire did eventually destroy whole baseships, so I stand corrected.
That makes a one on one confrontation with Saratoga problematic for Saratoga, which can't match the rate and volume of fire of the battlestars.
Still, it's not a huge
problem, since SCVNs exist decades in the future and the last battlestar was pyramid dunked into the sun 150,000 years ago.