"convenient as" is acceptable in written English.
You can use it to compare two things by expressing that one is more convenient than the other. For example, "Driving is more convenient as compared to taking the bus."
The volume controls on the left earpiece are convenient, as is the power button and power jack.
Several plot points are a little too convenient as well.
HEU is not as convenient as plutonium for making warheads.
"It wasn't as convenient as it was before".
"We want to make this as convenient as possible for them".
'So much history is airbrushed out as not being convenient, as challenging national myths.
Air travel has already become less convenient, as airlines have significantly cut capacity.
This isn't as convenient as the other units, which can be controlled purely with a smartphone.
And, of course, this method isn't nearly as convenient as a one-tap data app.
All in all, it's about as convenient as car rental could ever be.
As convenient as these cameras are, you probably shouldn't buy them.
