I have the Alpines 6000k and a friend has the GPs. The Alpines are rediculously bright. Cons, you have to runs some external wiring (simple install and reversible). GPs aren't quite as bright or white. They are difficult to see during the day. Pro, plug and play.
'13 35i M-Sport X3 | JB4 Stage 1 | BMS Intake | H&R Springs | Gloss black grill | CF Wrap and Coded by me | Recaro Child Seats
'15 M3 DCT AW/SO | JB Stage 1 | RKP Diffuser | P3 | M Perf Spoiler | iND Exterior Trim | Recaro Child Seat