When we want to use GPS in our mobile devices we have two choices: either to use device with GPS onboard (like N95, E90, 6110 navigator) or to use external bluetooth GPS device. Each choice has some pros and cons. In-built means only one (convergent) device in the pocket, but using more power and having lower sensivity circuit; external - means additional device with its own power supply (plus probably additional charger to take care of!), more sensitive GPS (in addition: accuracy may be increased thanks to WAAS/EGNOS to 1-3m as opposed to the normal 10-15m; there may be included a logger of visited positions), such device will use power for computations and data communication only (for example every 1sec + maintenance of connection).

I'm beginning to wonder which solution is better when we think about power consumption. The answer seems to be simple: mobile device + external GPS, but could you share your experience (maybe someone has made some real tests) on how longer will such configuration work (+30% more time?)