Tested 6.6.8:
On 6.6.7 GPS saw only 1-2 sattelites inside building, now it sees 6-9 satellites with 3 operational on 6.6.8
On 6.6.7 after quitting from Navitel - application crashed. On 6.6.8 it's fixed for me
GPS rather good now but not so good as on ZTE Z7 mini now. Still can be better