@Kelvin:
At the moment, I don't plan to use the 4G on the pyra.
(My Nokia 3510monochrome is doing a good job as phone)
But I ordered the 4G for two reasons:
1.: When my brave Nokia is decideing to die on me, the phone-software is hopefully good enough to use.
2.: The 4G model has manny sensores which the regular version doesn't have.
(GPS, barometric altitude sensor, compass, accelerator sensor,...)
With this sensors, the pyra will be able to replace my ca. 20 year old Blaupunkt GPS.
When you want this sensors, I'd recommend you to take the 4G model, even when you don't use the phone-function.