Auto. Faster in the 1/4 (stock), I've had zero issues with mine, a tune really wakes them up.
The manuals require regular maintenance on the clutch slave cylinder, frequent clutch fluid changes due to clutch dust getting past the seal and contaminating the fluid.
And you'll never need to replace the clutch in an auto (except at rebuild time).
'09 Pontiac G8 GXP, A6, Sunroof, MGM, #1664 of 1829
GMM RAMJET OTR CAI, Livernois E/TCM Tune, Kooks 1-7/8" LTs, catted mid-pipe, Hooker Polished SS MaxFlow mufflers - 394RWHP/386RWT
BMR Rear LCA's, stabilizer bars, end links, front LCA bushings, rear toe links and trailing arms, Pedders Street II kit, including subframe and diff bushings.
Hawk Ceramic pads, Brake Performance slotted and dimpled rotors, Russell stainless lines, Super Blue fluid.
Best 1/4 time - 12.52 @ 114.47, 1.94 60ft.