Antigravity Battery

I noticed my Antigravity RS battery was an ATZ7 which is only 3.3 Ah but it's never failed or seemed strained to start my Street Cup. Haven't tried starting it below freezing. When it dies, I'll replace it with the proper ATZ10 or bigger. Here are the specs for other Antigravity batteries compared to the stock battery:

OEM Yuasa - YTZ12: 11Ah ; 210 CCA
Dimensions (LWH):‎ 5.94 x 3.43 x 4.33 inches

ATZ7: 7 Ah (PbEq)/ 3.3 Ah (Actual) ; 150 CA
Dimensions (LWH): 4.53 x 2.75 x 3.35 inches

ATZ10: 12 Ah (PbEq)/ 6.1 Ah (Actual) ; 360 CA
Dimensions (LWH): 5.9 x 3.4 x 3.6 inches

ATX12: 12 Ah (PbEq)/ 6.1 Ah (Actual) ; 360 CA
Dimensions (LWH): 5.9 x 3.4 x 5.2 inches

ATX12HD: 16 Ah (PbEq)/ 8 Ah (Actual) ; 480 CA
Dimensions (LWH): 5.9 x 3.4 x 5.2 inches