reviews on the deepgroove brushless upgrade for Taig?

I just bought one and have yet to put it to use. I've run it without a load though and it is really noisy compared to the original AC motor. Is this normal for these models? I expected a BLDC to be really quiet. At full speed it's pretty harsh to listen to. At any speed (with no load) the RPM stutters around like a dragster at the starting line (this may very well be a normal no-load behavior but still, brushless tend to be very smooth)
I also discovered there is no way to control it with a PC :(