If you're more interested in driving, keep the GT.
If you're more interested in attention outside the club, get the LP640.
DBK, while I respect your opinion I do not agree. In South Florida (at least) lambo's are a dime a dozen and few people can differntiate between a Murcielago and an LP640.
If you want attention you get a Ford GT as it is more rare (anywhere actually).
If you want performance out of the box you get a Ford GT also.
If you want to spend more money you get an LP640.
I am not being bias, just stating facts.
BTW here is one speed list :
0-150MPH avearge trap times.
12.8 MCLAREN F1
13.2 PORSCHE CARRERA GT
16.8 FORD GT
17.4 LAMBORGHINI LP640
17.0 SALEEN S7
17.0 CORVETTE C6 Z06
18.0 FERRARI F40
18.7 FERRARI F50
19.5 LAMBORGHINI MURCIELAGO
19.7 PORSCHE 911 GT2 (996)
20.8 FERRARI 612 SCAGLIETTI
21.4 Ferrari F430
21.4 LAMBORGHINI GALLARDO
21.6 PORSCHE 911 TURBO (996)
22.1 FERRARI 575M MARANELLO
22.4 DODGE VIPER SRT-10 (2003)
23.7 MERCEDES BENZ CL600 (2004)
23.9 FERRARI 360 CHALLENGE STRADALE
23.9 PORSCHE 911 GT3 (996)
24.5 MERCEDES E55 AMG (2003)
25.5 CHEVROLET CORVETTE C5 Z06
25.6 ASTON MARTIN DB9
25.9 PORSCHE 911 TURBO TIPTRONIC (996)
26.4 PORSCHE 911 CARRERA S (997)
28.0 MERCEDES SLK55 AMG (2005)
29.6 FERRARI 360 MODENA SPYDER
29.7 LOTUS ESPRIT V8 TT
30.0 BMW E39 M5