Or, you could look at the NeoGPS pages that compare NeoGPS (duh), Adafruit_GPS, TinyGPS and TinyGPS++, in terms of RAM, program size and execution speed...
The NeoGPS benchmark sketch is included with the library: NMEAbenchmark.ino. It will show the execution time for any NeoGPS configuration, Nominal or custom. This configuration capability is unique to NeoGPS.
Cheers,
/dev