It is not the wattage that determine the brightness. It is the lumens value. HID are 35 watt whereas halogen bulb are 55 watt.
Most important thing for brightness is the focal length of the light source and the cleanliness of the reflector.
If you decide to go HID retrofit, make sure they are the right type of "bulb" eg H4.
and also they are canbus friendly. If there are not canbus friendly, you will get the dashboard showing that the bulb is blown.
Some people use a resistor, some people use a capacitor to cheat the error. There are some people who use a power relay
to switch the HID. All works except you dont know if the bulb is actually blown.
Another easy way is disable the diagnostic checking during start up via coding. That explain why your bulbs flicked when you
turn on the ignition.