depends on the beer you brewed. if its a belgian wit, 6 months is past its prime, even in the bottle.
if it was a porter that was oaked, it might just be coming into its prime.
I say, taste your two beers. If they are good, then they're good! You'll be able to taste if they're getting funky or stale.
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10