Here are my impression for what I tested until now.
Time to get a fix
The first time I switch the watch ON, I got a fix very quickly (less than 1 minute).
But some times, even in open space and sunny sky it takes a long time to fix (with the pop up "reset GPS")
Maybe am I swinging my arms too much when running, but the watch always give me a longer distance than that I used to do.
When I download the trackpoints I see that it did not follow correctly the track. For instance, when I run along a staight raod, I see the trackpoint crossing the road and then back again to the side where I was.
Last time I did a 14k run, and the watch tells me 14,8k.
I did use the heart belt each time, perhaps some interferences with the gps, as some others discovered before ?
It's a shame because the heartbelt works fine.
good point, cumul+ and cumul- are virtually identical when running a loop circuit.
bad point, the value computed did not reflect the truth.
It is quite reliable when climbing constantly for kilometers with a clear sky (eg moutain road).
It became worse when running in the wood, with successive uphill, downhill for 200-500m each.
This point was already discussed in the slope algorithm discussion.
Maybe I can test a beta firmware with new slope algorithm if one available ?
Improvement for the VP:
it should be nice if the VP can be add to the custom screens when VP enabled.
Actually, when the VP is activated, you can go back to the custom screen to monitor your run and look at the pop up for the VP when you ear them.
If you switch off the sound of the pop up, it is hard to get the information unless you are all the time looking your watch and not your run.
improvement wish :
when configuring the watch, you could choose to add the VP in the custom screen (when VP is activated), maybe in a 5th screen or even replacing one of the other if the watch can only drive 4 screens.
The VP screen will just have the same message as inside the pop up, at the refresh rate of the pop up. Maybe it can be set on a split screen (2 informations), so that you can see something else with the VP.
The main advantage is that you can look at the VP status (above/behind dist/time) each time you want.
Improvement that could be fun and not so complicated to add:
adding fitness test like Cooper test or half Cooper.
Of course you can programm the watch to do it for you, but if you set this function apart in a special submenu in Activity for instance, you can store the results and show a progress curve or calculate speed index and so on.