I have mine on all the time, purely as a rough guide for where I’m going and for an ETA. It fits into the money slot on the dash so keeps the windscreen clear. For traffic info and detailed maps/streetview I use my iPhone 
on all the time for me,its handy as you can pan out of the maps and look at surrounding roads etc,or if a road is closed off its quite handy
on all the time as mostlyabove
cameras etc aslo to update log of cafes
see one with good parking its in
Eyeball Mk1 here. Don’t even own one.
I do have a crappy old Nokia E61 (no GPS wotsit) with Google Maps to dig me out of bother if I really get stuck.
LOL…“use it for detection of speed cameras,”…stick to the limits and wouldnt need it 
Anyway, got one and very handy for finding those places that google earth doesnt give a good indication too over water or over here.
Best off with out one rely
Never learn anything with it
They all ways say its for people that cant read a map
bubsy06:
I have it on all the time, it is more than just some woman dishing out directions.
It gives me warnings about speed cameras, also gives me traffic updates, shows me where the nearest garages are, and gives me a guide of upcoming bends in the road so I can be prepared for them.
can a paper map do all that
Im exactly the same
I’ve still not bought one,maps are the future ! 
I use a TT950 when nessesary, mainly for the live traffic, etas and PGPS speed camera POI database (which I have a lifetime subscription) to keep me on my toes. Though doing multidrop last week down around Bala, Cearnarfon, & Portmerion, the thing decided to loose GPS status for several hours causing some amusing errors & eyeball 1 had to be deployed as backup. Though after resetting the factory defaults, Id found myself spending several hours over the following days resetting the proximety alerts for the huge number of POIs (speed cameras, bridge hights fuel etc.) that I have stored in the device. I wouldnt want to have to do that again in a hurry. 
The TT live services I`ve found quite useful, especially the google search which allows me to locate the exact customer site
got a tom tom sat nav had it 5 years possibly longer and its great for ETA to places or finding new places never been to before but still have paper maps and iphone for street view which is handy…
I also listen to my sat nav like i listen to my wife…not much