The item is working perfectly. The AGPS also gives it an advantage against the previous model the 4043 and other competitor ones.
It is quite accurate. Indoors the signal is less accurate and it could result in tracking a bit faraway from where it actually is but it never loses the signal so it is a great device and competes very well with other similar AGPS. It will work in your bag as if it was in your hand. Don't worry about clothes or bags as the device will be very sensitive, I've tested it.
I extract the gpx file from the device using the application provided with the item, GPS Photo Tagger. If you only shoot in jpeg it will be quite a good and reliable application, also very easy to use. But if you shoot raw files (cr2 in my case) you will need one of the many free applications available, I use one called Geosetter to tag all kind of pictures supported by Exif tool.
Its built is not weather sealed but strong for all applications, bring a small saleable bag, like those you can buy in food stores or in diving specialized stores and bring it with you; in case you happen to be in estreme weather conditions it will be protected from getting wet.
Batteries can be found on Amazon for quite a cheap price and I'm sure I'll buy a second battery just for a peace of mind for when I'm travelling far and in remote places. The standard usb charging connector ensures that the battery can be recharged in many different ways, including solar.
I see the model 4043 is selling more times for the same price, buy the 4044 and don't be concerned about low rating, the 4044 is better than the 4043.
The seller was courteous, answering promptly to my messages when I didn't receive the item due to the snow storm which affected all UK. I will buy again with confidence.