Quote Originally Posted by catymag View Post
Phone batteries don't last that long using GPS.
Outdoors transflective displays are made to be seen in sunlight and with sunglasses and you can use it with gloves.
GPS outdoor units are far more robust than a phone.
A dedicated handheld has better accuracy. (under forest canopy for example: no question the Garmin is far more accurate).
A Garmin handheld offers some interesting features like sight n’ go. Units with 3-axis electronic compass can be used when idle or moving at low speeds, Glonass/waas support are also a plus for better precision.
3-axis compass is also tilt compensated, meaning the device can be held in any position and will still give a compass reading.
Most GPS receivers in phones work not nearly as good as stand-alone GPS devices. Usually, one wouldn't notice this because phones use assisted GPS, but you can make a test:
You can test how well your phone works by downloading the app GPS Status & Toolbox, disable all data connections (Wifi and mobile), reset the AGPS data using that app, restart the phone and then get the GPS position. You will notice that it is very slow. After the phone got a first fix, try to close all apps using GPS, wait a few minutes and try to get the position again. Do the same but restart the phone. This should give you a realistic estimation of how well your phone will serve you without an internet connection, for example when gsm is not available in the mountains.
I can't argued against battery battery nor screen. My only dedicated unit Nuvi765 couldn't even hold a charge after more than 5 min; so I can't speak for it. But I know for sure that the compass in my Moto-G works just as well as any GPS unit. Most (if not all) android device have GPS receiver (some better than others) because it's so cheap to put chipset in SOC. This is stand alone GPS via SiRF chip and not assisted GPS via cell tower triangulation. I also use my android phone as offline nav and doesn't activate nor depend on wifi and it has been no problem. All GPS receiver in stand-alone unit or phone follow protocol when doing position lock. The time it takes depend on how accurate your current clock is. Handheld unit might use multiple channels to get faster fix. I did a test with Moto-G and cold reboot to lock is less than 5-10 secs after starting app with no data nor wifi connection. It takes much less when just restarting the app. The only thing that changes between the phone is how sensitive the receivers are. The Moto-G can lock indoor while a lesser phone couldn't. If the clock on the phone drift or set wrong, then the lock is much longer. But if you got the money, why not get a dedicated unit.