Stable voltage for a Raspberry Pi B + with PiTFT and three USB Devices

I run the Pi with
- A 2.8 "capacitive touchscreen of Adafruit
- A Logitech Unifying receiver Logitech K830 keyboard for a
- An Edimax EW-7811Un Wireless USB Adapter
- A D-Link Wireless N 150 Micro USB Adapter

The power supply when booting the Pi ~ 5.04V, with a consumption of about 0.3A.
After booting, including active TFT, two active wireless connections, in idle mode, it delivers 4,93V at 0,43A.
Underload, including active TFT, and traffic over a wireless connection, it provides 4,93V at 0.5A.

I have been able to detect any problem with the power supply, the power supply seems considerably more stable than many other power supplies to be, perhaps it is also because the Pi + B has been improved in this direction.