Thanks for your comments. With regard to your questions, I'll do my best:
Screen - as far as I am concerned it is Gorilla glass, although I have not tested it for obvious reasons. G3 was Gorilla so why would it be changed for G3S. It feels like glass, just like that of the G3.
FM Radio - the range is 87.5 to 108MHz. You can save up to 14 frequencies. There is an autosearch feature that stores its findings in a list. In my case it only found 9 frequencies that it felt were strong enough to save in the list but I was able to save 5 more weaker stations manually. There is a toggle facility to move from one saved station to the next in the list, or the previous one, just like an MP3 player.
Of the 14 saved stations only 5 of them can be designated as "Favourites". The only benefit of being a favourite is that you can manually give it a name, which will display when that station is playing. The "non-favourites" in the list are identified just by the frequency when they are selected.
The sound quality I would say is good. This obviously is influenced by broadcast and earphone quality. On a good station with quiet speech I could not detect much in the way of background hiss and the overall tone on music is reasonable.
The FM radio feature is a true radio, not an internet feature transmitting FM stations. As such it requires an earphone to be inserted for its operation, as this also acts as the aerial. There is a selection that diverts the sound to the built in speaker but I noticed that the volume seemed quite low in this mode (ie. lower than when playing MP3 music through the speaker). An odd result but not one that is likely to be important to most people.
I can find no means of altering the tone either by graphic equaliser or bass boost, but I expect this requirement could be met by an appropriatte app. However, the sound quality through my cheap earphones seemed quite good, including the bass quality.
One other feature is the ability to make a recording of a broadcast.
That's it. You now know as much as me about the FM feature, which I do not normally use. I hope I have been able to help.
Hi RoVlad - this could be your lucky day. I have news about G3S GPS performance and it's good.
Like you I own a G3, bought in November, so using the original A500 chipset, unlike your G3N. Overall a good mobile for the price but a couple of weak areas. In my case the cellphone signal is weaker than I would like and weaker than my wife's G3, which is also on the original chipset but bought in January. The second weak point is the GPS. I can get a fix indoors next to a window and obviously outdoors. This is usually with the aid of AGPS, EPO etc. but in use the signal is prone to dropout which can be a nuisance if being used for car navigation. I wanted to use GPS in my car but after trials decided it was impractical. I was even considering fitting my car with a GPS booster device.
Then one day I was surfing everyones favourite auction site. I was not really looking to change my mobile when I saw a G3S on auction from Hong Kong. I was aware of its existence and its spec so I thought why not place a bid. This I did and won the phone for £101 delivered. Result! Even better when it arrived by airmail in 7 days. It could easily have been 30 days.
My view was that I could always sell the G3 and that the Jiayu may have learnt a few lessons before marketing the G3S. I was not disappointed.
I find the uprated processor gives the G3S faster performance when surfing, the cellphone signal is improved for me, but this obviously depends on where you are and who your provider is.
On wifi my maximum speed is 54Mbps which is the G standard but my router cannot handle a higher rate than this so I cannot tell if the phone could give the N standard which is 150Mbps. Maybe it can but Jiayu spec details are unclear. I think the new chipset caters for the N standard but don't know if Jiayu have implemented that feature like they probably have on the G4.
Anyway, enough of all that. I now have a phone where the GPS is acceptable. I have only had it for 2 weeks but have done one 10 mile navigation in my car that was completely successful, with no signal dropouts, albeit on a sunny day. I now am able to get a fix indoors away from a window and obviously outdoors. I just tried getting a cold fix outdoors without using AGPS and it took 80 secs initially from cold. Subsequent fixes could be got within 5 secs.
Normally, I use AGPS and EPO assistance and an outdoor cold fix can be expected within 20 or 30 secs.
I have taken advantage of certain Apps to aid this process. FasterGPS is used once to ensure your mobile uses the correct NTP server (ie. for UK in my case). Normally, I also use GPS Test for firing up the GPS, selecting EPO and AGPS, and for clearing old AGPS data before updating with fresh AGPS data.
One other bonus for the G3S`is that full HD 1080 video can be shot, although it is quite hungry on storage in this mode. Not to mention Jellybean 4.2.1 which in this case is a Lewa version.
I took a stab in the dark by buying the G3S. I am not disappointed.
I hope this info is of some use to you, even though I have rambled a bit.